diff --git a/ast/src/main/ast/pork.yml b/ast/src/main/ast/pork.yml
index 0947aa9..a33d9ae 100644
--- a/ast/src/main/ast/pork.yml
+++ b/ast/src/main/ast/pork.yml
@@ -59,13 +59,22 @@ types:
       type: Expression
     - name: typeSpec
       type: TypeSpec?
-  SetAssignment:
+  SymbolSetAssignment:
     parent: Expression
     values:
     - name: symbol
       type: Symbol
     - name: value
       type: Expression
+  IndexedSetAssignment:
+    parent: Expression
+    values:
+      - name: target
+        type: Expression
+      - name: index
+        type: Expression
+      - name: value
+        type: Expression
   InfixOperator:
     values:
     - name: token
diff --git a/ast/src/main/graph/types.dot b/ast/src/main/graph/types.dot
index e7e5023..d00c9d1 100644
--- a/ast/src/main/graph/types.dot
+++ b/ast/src/main/graph/types.dot
@@ -10,7 +10,8 @@ digraph A {
   type_CompilationUnit [shape=box,label="CompilationUnit"]
   type_LetAssignment [shape=box,label="LetAssignment"]
   type_VarAssignment [shape=box,label="VarAssignment"]
-  type_SetAssignment [shape=box,label="SetAssignment"]
+  type_SymbolSetAssignment [shape=box,label="SymbolSetAssignment"]
+  type_IndexedSetAssignment [shape=box,label="IndexedSetAssignment"]
   type_InfixOperator [shape=box,label="InfixOperator"]
   type_InfixOperation [shape=box,label="InfixOperation"]
   type_BooleanLiteral [shape=box,label="BooleanLiteral"]
@@ -57,7 +58,8 @@ digraph A {
   type_Node -> type_NativeTypeDescriptor
   type_Expression -> type_LetAssignment
   type_Expression -> type_VarAssignment
-  type_Expression -> type_SetAssignment
+  type_Expression -> type_SymbolSetAssignment
+  type_Expression -> type_IndexedSetAssignment
   type_Expression -> type_InfixOperation
   type_Expression -> type_BooleanLiteral
   type_Expression -> type_FunctionCall
@@ -94,8 +96,9 @@ digraph A {
   type_VarAssignment -> type_Symbol [style=dotted]
   type_VarAssignment -> type_Expression [style=dotted]
   type_VarAssignment -> type_TypeSpec [style=dotted]
-  type_SetAssignment -> type_Symbol [style=dotted]
-  type_SetAssignment -> type_Expression [style=dotted]
+  type_SymbolSetAssignment -> type_Symbol [style=dotted]
+  type_SymbolSetAssignment -> type_Expression [style=dotted]
+  type_IndexedSetAssignment -> type_Expression [style=dotted]
   type_InfixOperation -> type_Expression [style=dotted]
   type_InfixOperation -> type_InfixOperator [style=dotted]
   type_FunctionCall -> type_Symbol [style=dotted]
diff --git a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/IndexedSetAssignment.kt b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/IndexedSetAssignment.kt
new file mode 100644
index 0000000..886dcc4
--- /dev/null
+++ b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/IndexedSetAssignment.kt
@@ -0,0 +1,30 @@
+// GENERATED CODE FROM PORK AST CODEGEN
+package gay.pizza.pork.ast.gen
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+@SerialName("indexedSetAssignment")
+class IndexedSetAssignment(val target: Expression, val index: Expression, val value: Expression) : Expression() {
+  override val type: NodeType = NodeType.IndexedSetAssignment
+
+  override fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> =
+    visitor.visitNodes(target, index, value)
+
+  override fun <T> visit(visitor: NodeVisitor<T>): T =
+    visitor.visitIndexedSetAssignment(this)
+
+  override fun equals(other: Any?): Boolean {
+    if (other !is IndexedSetAssignment) return false
+    return other.target == target && other.index == index && other.value == value
+  }
+
+  override fun hashCode(): Int {
+    var result = target.hashCode()
+    result = 31 * result + index.hashCode()
+    result = 31 * result + value.hashCode()
+    result = 31 * result + type.hashCode()
+    return result
+  }
+}
diff --git a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeCoalescer.kt b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeCoalescer.kt
index 4f1092c..0a925ce 100644
--- a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeCoalescer.kt
+++ b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeCoalescer.kt
@@ -47,6 +47,9 @@ class NodeCoalescer(val followChildren: Boolean = true, val handler: (Node) -> U
   override fun visitIndexedBy(node: IndexedBy): Unit =
     handle(node)
 
+  override fun visitIndexedSetAssignment(node: IndexedSetAssignment): Unit =
+    handle(node)
+
   override fun visitInfixOperation(node: InfixOperation): Unit =
     handle(node)
 
@@ -83,9 +86,6 @@ class NodeCoalescer(val followChildren: Boolean = true, val handler: (Node) -> U
   override fun visitReturn(node: Return): Unit =
     handle(node)
 
-  override fun visitSetAssignment(node: SetAssignment): Unit =
-    handle(node)
-
   override fun visitStringLiteral(node: StringLiteral): Unit =
     handle(node)
 
@@ -98,6 +98,9 @@ class NodeCoalescer(val followChildren: Boolean = true, val handler: (Node) -> U
   override fun visitSymbolReference(node: SymbolReference): Unit =
     handle(node)
 
+  override fun visitSymbolSetAssignment(node: SymbolSetAssignment): Unit =
+    handle(node)
+
   override fun visitTypeDefinition(node: TypeDefinition): Unit =
     handle(node)
 
diff --git a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeParser.kt b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeParser.kt
index 98dcb80..50b036e 100644
--- a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeParser.kt
+++ b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeParser.kt
@@ -38,6 +38,8 @@ interface NodeParser {
 
   fun parseIndexedBy(): IndexedBy
 
+  fun parseIndexedSetAssignment(): IndexedSetAssignment
+
   fun parseInfixOperation(): InfixOperation
 
   fun parseIntegerLiteral(): IntegerLiteral
@@ -62,8 +64,6 @@ interface NodeParser {
 
   fun parseReturn(): Return
 
-  fun parseSetAssignment(): SetAssignment
-
   fun parseStringLiteral(): StringLiteral
 
   fun parseSuffixOperation(): SuffixOperation
@@ -72,6 +72,8 @@ interface NodeParser {
 
   fun parseSymbolReference(): SymbolReference
 
+  fun parseSymbolSetAssignment(): SymbolSetAssignment
+
   fun parseTypeDefinition(): TypeDefinition
 
   fun parseTypeSpec(): TypeSpec
diff --git a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeParserExtensions.kt b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeParserExtensions.kt
index 1df8cbf..a36c0c8 100644
--- a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeParserExtensions.kt
+++ b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeParserExtensions.kt
@@ -12,7 +12,8 @@ fun NodeParser.parse(type: NodeType): Node =
     NodeType.CompilationUnit -> parseCompilationUnit()
     NodeType.LetAssignment -> parseLetAssignment()
     NodeType.VarAssignment -> parseVarAssignment()
-    NodeType.SetAssignment -> parseSetAssignment()
+    NodeType.SymbolSetAssignment -> parseSymbolSetAssignment()
+    NodeType.IndexedSetAssignment -> parseIndexedSetAssignment()
     NodeType.InfixOperation -> parseInfixOperation()
     NodeType.BooleanLiteral -> parseBooleanLiteral()
     NodeType.FunctionCall -> parseFunctionCall()
diff --git a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeType.kt b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeType.kt
index 324ab08..cd9956d 100644
--- a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeType.kt
+++ b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeType.kt
@@ -21,6 +21,7 @@ enum class NodeType(val parent: NodeType? = null) {
   ImportDeclaration(Declaration),
   ImportPath(Node),
   IndexedBy(Expression),
+  IndexedSetAssignment(Expression),
   InfixOperation(Expression),
   IntegerLiteral(Expression),
   LetAssignment(Expression),
@@ -33,11 +34,11 @@ enum class NodeType(val parent: NodeType? = null) {
   Parentheses(Expression),
   PrefixOperation(Expression),
   Return(Expression),
-  SetAssignment(Expression),
   StringLiteral(Expression),
   SuffixOperation(Expression),
   Symbol(Node),
   SymbolReference(Expression),
+  SymbolSetAssignment(Expression),
   TypeDefinition(Definition),
   TypeSpec(Node),
   VarAssignment(Expression),
diff --git a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeVisitor.kt b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeVisitor.kt
index 4ed8763..d86ede2 100644
--- a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeVisitor.kt
+++ b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeVisitor.kt
@@ -32,6 +32,8 @@ interface NodeVisitor<T> {
 
   fun visitIndexedBy(node: IndexedBy): T
 
+  fun visitIndexedSetAssignment(node: IndexedSetAssignment): T
+
   fun visitInfixOperation(node: InfixOperation): T
 
   fun visitIntegerLiteral(node: IntegerLiteral): T
@@ -56,8 +58,6 @@ interface NodeVisitor<T> {
 
   fun visitReturn(node: Return): T
 
-  fun visitSetAssignment(node: SetAssignment): T
-
   fun visitStringLiteral(node: StringLiteral): T
 
   fun visitSuffixOperation(node: SuffixOperation): T
@@ -66,6 +66,8 @@ interface NodeVisitor<T> {
 
   fun visitSymbolReference(node: SymbolReference): T
 
+  fun visitSymbolSetAssignment(node: SymbolSetAssignment): T
+
   fun visitTypeDefinition(node: TypeDefinition): T
 
   fun visitTypeSpec(node: TypeSpec): T
diff --git a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeVisitorExtensions.kt b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeVisitorExtensions.kt
index 71dce30..d789294 100644
--- a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeVisitorExtensions.kt
+++ b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/NodeVisitorExtensions.kt
@@ -9,7 +9,8 @@ fun <T> NodeVisitor<T>.visit(node: Node): T =
     is CompilationUnit -> visitCompilationUnit(node)
     is LetAssignment -> visitLetAssignment(node)
     is VarAssignment -> visitVarAssignment(node)
-    is SetAssignment -> visitSetAssignment(node)
+    is SymbolSetAssignment -> visitSymbolSetAssignment(node)
+    is IndexedSetAssignment -> visitIndexedSetAssignment(node)
     is InfixOperation -> visitInfixOperation(node)
     is BooleanLiteral -> visitBooleanLiteral(node)
     is FunctionCall -> visitFunctionCall(node)
diff --git a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/SetAssignment.kt b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/SymbolSetAssignment.kt
similarity index 69%
rename from ast/src/main/kotlin/gay/pizza/pork/ast/gen/SetAssignment.kt
rename to ast/src/main/kotlin/gay/pizza/pork/ast/gen/SymbolSetAssignment.kt
index 67a30bc..b6e061e 100644
--- a/ast/src/main/kotlin/gay/pizza/pork/ast/gen/SetAssignment.kt
+++ b/ast/src/main/kotlin/gay/pizza/pork/ast/gen/SymbolSetAssignment.kt
@@ -5,18 +5,18 @@ import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
 @Serializable
-@SerialName("setAssignment")
-class SetAssignment(val symbol: Symbol, val value: Expression) : Expression() {
-  override val type: NodeType = NodeType.SetAssignment
+@SerialName("symbolSetAssignment")
+class SymbolSetAssignment(val symbol: Symbol, val value: Expression) : Expression() {
+  override val type: NodeType = NodeType.SymbolSetAssignment
 
   override fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> =
     visitor.visitNodes(symbol, value)
 
   override fun <T> visit(visitor: NodeVisitor<T>): T =
-    visitor.visitSetAssignment(this)
+    visitor.visitSymbolSetAssignment(this)
 
   override fun equals(other: Any?): Boolean {
-    if (other !is SetAssignment) return false
+    if (other !is SymbolSetAssignment) return false
     return other.symbol == symbol && other.value == value
   }
 
diff --git a/bir/src/main/kotlin/gay/pizza/pork/bir/IrIndex.kt b/bir/src/main/kotlin/gay/pizza/pork/bir/IrIndex.kt
index f25d47c..ea53797 100644
--- a/bir/src/main/kotlin/gay/pizza/pork/bir/IrIndex.kt
+++ b/bir/src/main/kotlin/gay/pizza/pork/bir/IrIndex.kt
@@ -3,9 +3,12 @@ package gay.pizza.pork.bir
 import kotlinx.serialization.Serializable
 
 @Serializable
-data class IrIndex(var data: IrCodeElement, var index: IrCodeElement) : IrCodeElement() {
+data class IrIndex(var data: IrCodeElement, var index: IrCodeElement, var value: IrCodeElement? = null) : IrCodeElement() {
   override fun crawl(block: (IrElement) -> Unit) {
     block(data)
     block(index)
+    if (value != null) {
+      block(value!!)
+    }
   }
 }
diff --git a/bytecode/src/main/kotlin/gay/pizza/pork/bytecode/Opcode.kt b/bytecode/src/main/kotlin/gay/pizza/pork/bytecode/Opcode.kt
index 6b7cc2d..1dfd049 100644
--- a/bytecode/src/main/kotlin/gay/pizza/pork/bytecode/Opcode.kt
+++ b/bytecode/src/main/kotlin/gay/pizza/pork/bytecode/Opcode.kt
@@ -40,6 +40,7 @@ enum class Opcode(val id: UByte) {
   EuclideanModulo(37u),
   Remainder(38u),
   Index(39u),
+  IndexSet(44u),
   ScopeIn(40u),
   ScopeOut(41u),
   ReturnAddress(42u),
diff --git a/compiler/src/main/kotlin/gay/pizza/pork/compiler/AstIrEmitter.kt b/compiler/src/main/kotlin/gay/pizza/pork/compiler/AstIrEmitter.kt
index bf24a07..50e6e52 100644
--- a/compiler/src/main/kotlin/gay/pizza/pork/compiler/AstIrEmitter.kt
+++ b/compiler/src/main/kotlin/gay/pizza/pork/compiler/AstIrEmitter.kt
@@ -228,6 +228,12 @@ class AstIrEmitter(
     index = visit(node.index)
   )
 
+  override fun visitIndexedSetAssignment(node: IndexedSetAssignment): IrCodeElement = IrIndex(
+    data = visit(node.target),
+    index = visit(node.index),
+    value = visit(node.value),
+  )
+
   override fun visitInfixOperation(node: InfixOperation): IrCodeElement {
     val op = when (node.op) {
       InfixOperator.Plus -> IrInfixOp.Add
@@ -288,7 +294,7 @@ class AstIrEmitter(
   override fun visitReturn(node: Return): IrCodeElement =
     IrReturn(from = self, value = node.value.visit(this))
 
-  override fun visitSetAssignment(node: SetAssignment): IrCodeElement {
+  override fun visitSymbolSetAssignment(node: SymbolSetAssignment): IrCodeElement {
     val symbol = lookupLocalVariable(node.symbol) ?:
       throw CompileError("Unable to find local variable target '${node.symbol.id}'", node)
     return IrStore(symbol, node.value.visit(this))
diff --git a/compiler/src/main/kotlin/gay/pizza/pork/compiler/IrStubOpEmitter.kt b/compiler/src/main/kotlin/gay/pizza/pork/compiler/IrStubOpEmitter.kt
index 3ef1617..5601918 100644
--- a/compiler/src/main/kotlin/gay/pizza/pork/compiler/IrStubOpEmitter.kt
+++ b/compiler/src/main/kotlin/gay/pizza/pork/compiler/IrStubOpEmitter.kt
@@ -248,9 +248,16 @@ class IrStubOpEmitter(val irDefinition: IrDefinition, val code: CodeBuilder) : I
   }
 
   override fun visitIrIndex(ir: IrIndex) {
+    if (ir.value != null) {
+      visit(ir.value!!)
+    }
     visit(ir.index)
     visit(ir.data)
-    code.emit(Opcode.Index)
+    if (ir.value != null) {
+      code.emit(Opcode.IndexSet)
+    } else {
+      code.emit(Opcode.Index)
+    }
   }
 
   override fun visitIrListSize(ir: IrListSize) {
diff --git a/evaluator/src/main/kotlin/gay/pizza/pork/evaluator/EvaluationVisitor.kt b/evaluator/src/main/kotlin/gay/pizza/pork/evaluator/EvaluationVisitor.kt
index 6a93445..3279f81 100644
--- a/evaluator/src/main/kotlin/gay/pizza/pork/evaluator/EvaluationVisitor.kt
+++ b/evaluator/src/main/kotlin/gay/pizza/pork/evaluator/EvaluationVisitor.kt
@@ -177,7 +177,7 @@ class EvaluationVisitor(root: Scope, val stack: CallStack) : FunctionLevelVisito
     return previousValue
   }
 
-  override fun visitSetAssignment(node: SetAssignment): Any {
+  override fun visitSymbolSetAssignment(node: SymbolSetAssignment): Any {
     val value = node.value.visit(this)
     currentScope.set(node.symbol.id, value)
     return value
@@ -399,6 +399,24 @@ class EvaluationVisitor(root: Scope, val stack: CallStack) : FunctionLevelVisito
     throw RuntimeException("Failed to index '${value}' by '${index}': Unsupported types used.")
   }
 
+  override fun visitIndexedSetAssignment(node: IndexedSetAssignment): Any {
+    val value = node.value.visit(this)
+    val index = node.index.visit(this)
+    val target = node.target.visit(this)
+    if (target is MutableList<*> && index is Number) {
+      @Suppress("UNCHECKED_CAST")
+      (target as MutableList<Any?>)[index.toInt()] = value
+      return None
+    }
+
+    if (target is Array<*> && index is Number) {
+      @Suppress("UNCHECKED_CAST")
+      (target as MutableList<Any?>)[index.toInt()] = value
+      return None
+    }
+    return value
+  }
+
   override fun visitNoneLiteral(node: NoneLiteral): Any = None
 
   override fun visitContinue(node: Continue): Any = ContinueMarker
diff --git a/examples/gameoflife/gameoflife.pork b/examples/gameoflife/gameoflife.pork
index 8e91dd4..16e26fc 100644
--- a/examples/gameoflife/gameoflife.pork
+++ b/examples/gameoflife/gameoflife.pork
@@ -73,8 +73,8 @@ func setCell(cells, swap, x, y, state) {
     let mask = if swap { 2 } else { 1 }
     let idx = x + y * gridWidth
     let value = cells[idx]
-    if state { listSet(cells, idx, value | mask) }
-    else     { listSet(cells, idx, value & (~mask)) }
+    if state { cells[idx] = value | mask }
+    else     { cells[idx] = value & (~mask) }
   }
 }
 
diff --git a/examples/index.pork b/examples/index.pork
index d3ecdea..71218c9 100644
--- a/examples/index.pork
+++ b/examples/index.pork
@@ -1,4 +1,6 @@
 export func main() {
   let items = [["Hello"], ["Goodbye"]]
   println(items[0][0])
+  items[0][0] = "Goodbye"
+  println(items[0][0])
 }
diff --git a/frontend/src/main/kotlin/gay/pizza/pork/frontend/scope/ExternalSymbolUsageAnalyzer.kt b/frontend/src/main/kotlin/gay/pizza/pork/frontend/scope/ExternalSymbolUsageAnalyzer.kt
index 8c67376..9108184 100644
--- a/frontend/src/main/kotlin/gay/pizza/pork/frontend/scope/ExternalSymbolUsageAnalyzer.kt
+++ b/frontend/src/main/kotlin/gay/pizza/pork/frontend/scope/ExternalSymbolUsageAnalyzer.kt
@@ -2,6 +2,7 @@ package gay.pizza.pork.frontend.scope
 
 import gay.pizza.pork.ast.FunctionLevelVisitor
 import gay.pizza.pork.ast.gen.*
+import gay.pizza.pork.ast.gen.visit
 
 class ExternalSymbolUsageAnalyzer : FunctionLevelVisitor<Unit>() {
   private val symbols = mutableSetOf<Symbol>()
@@ -116,8 +117,13 @@ class ExternalSymbolUsageAnalyzer : FunctionLevelVisitor<Unit>() {
     node.visitChildren(this)
   }
 
-  override fun visitSetAssignment(node: SetAssignment) {
-    node.value.visit(this)
+  override fun visitSymbolSetAssignment(node: SymbolSetAssignment) {
+    checkAndContribute(node.symbol)
+    node.visitChildren(this)
+  }
+
+  override fun visitIndexedSetAssignment(node: IndexedSetAssignment) {
+    node.visitChildren(this)
   }
 
   override fun visitStringLiteral(node: StringLiteral) {
diff --git a/parser/src/main/kotlin/gay/pizza/pork/parser/Parser.kt b/parser/src/main/kotlin/gay/pizza/pork/parser/Parser.kt
index e66b8e6..00abaf5 100644
--- a/parser/src/main/kotlin/gay/pizza/pork/parser/Parser.kt
+++ b/parser/src/main/kotlin/gay/pizza/pork/parser/Parser.kt
@@ -53,16 +53,6 @@ class Parser(source: TokenSource, attribution: NodeAttribution) :
       }
     }
 
-    if (expression is SymbolReference && peek(TokenType.Equals)) {
-      val symbolReference = expression
-      expression = produce(NodeType.SetAssignment) {
-        attribution.adopt(expression)
-        expect(TokenType.Equals)
-        val value = parseExpression()
-        SetAssignment(symbolReference.symbol, value)
-      }
-    }
-
     while (peek(TokenType.LeftBracket)) {
       expression = produce(NodeType.IndexedBy) {
         attribution.adopt(expression)
@@ -73,12 +63,33 @@ class Parser(source: TokenSource, attribution: NodeAttribution) :
       }
     }
 
+    if (expression is SymbolReference && peek(TokenType.Equals)) {
+      val symbolReference = expression
+      expression = produce(NodeType.SymbolSetAssignment) {
+        attribution.adopt(expression)
+        expect(TokenType.Equals)
+        val value = parseExpression()
+        SymbolSetAssignment(symbolReference.symbol, value)
+      }
+    }
+
+    if (expression is IndexedBy && peek(TokenType.Equals)) {
+      val indexedBy = expression
+      expression = produce(NodeType.IndexedSetAssignment) {
+        attribution.adopt(indexedBy)
+        expect(TokenType.Equals)
+        val value = parseExpression()
+        IndexedSetAssignment(target = indexedBy.expression, index = indexedBy.index, value = value)
+      }
+    }
+
     return if (peek(
         TokenType.Plus, TokenType.Minus, TokenType.Multiply, TokenType.Divide, TokenType.Ampersand,
         TokenType.Pipe, TokenType.Caret, TokenType.Equality, TokenType.Inequality, TokenType.Mod,
         TokenType.Rem, TokenType.Lesser, TokenType.Greater, TokenType.LesserEqual, TokenType.GreaterEqual,
         TokenType.And, TokenType.Or)) {
       produce(NodeType.InfixOperation) {
+        attribution.adopt(expression)
         val infixToken = next()
         val infixOperator = ParserHelpers.convertInfixOperator(infixToken)
         InfixOperation(expression, infixOperator, parseExpression())
@@ -263,6 +274,16 @@ class Parser(source: TokenSource, attribution: NodeAttribution) :
     IndexedBy(expression, index)
   }
 
+  override fun parseIndexedSetAssignment(): IndexedSetAssignment = produce(NodeType.IndexedSetAssignment) {
+    val target = parseExpression()
+    expect(TokenType.LeftBracket)
+    val index = parseExpression()
+    expect(TokenType.RightBracket)
+    expect(TokenType.Equals)
+    val value = parseExpression()
+    IndexedSetAssignment(target, index, value)
+  }
+
   override fun parseInfixOperation(): InfixOperation = produce(NodeType.InfixOperation) {
     val infixToken = next()
     val infixOperator = ParserHelpers.convertInfixOperator(infixToken)
@@ -363,11 +384,11 @@ class Parser(source: TokenSource, attribution: NodeAttribution) :
     Return(parseExpression())
   }
 
-  override fun parseSetAssignment(): SetAssignment = produce(NodeType.SetAssignment) {
+  override fun parseSymbolSetAssignment(): SymbolSetAssignment = produce(NodeType.SymbolSetAssignment) {
     val symbol = parseSymbol()
     expect(TokenType.Equals)
     val value = parseExpression()
-    SetAssignment(symbol, value)
+    SymbolSetAssignment(symbol, value)
   }
 
   override fun parseStringLiteral(): StringLiteral = produce(NodeType.StringLiteral) {
diff --git a/parser/src/main/kotlin/gay/pizza/pork/parser/Printer.kt b/parser/src/main/kotlin/gay/pizza/pork/parser/Printer.kt
index 3579a1d..e580103 100644
--- a/parser/src/main/kotlin/gay/pizza/pork/parser/Printer.kt
+++ b/parser/src/main/kotlin/gay/pizza/pork/parser/Printer.kt
@@ -202,7 +202,7 @@ class Printer(buffer: StringBuilder) : NodeVisitor<Unit> {
     append(node.op.token)
   }
 
-  override fun visitSetAssignment(node: SetAssignment) {
+  override fun visitSymbolSetAssignment(node: SymbolSetAssignment) {
     visit(node.symbol)
     append(" = ")
     visit(node.value)
@@ -304,6 +304,15 @@ class Printer(buffer: StringBuilder) : NodeVisitor<Unit> {
     append("]")
   }
 
+  override fun visitIndexedSetAssignment(node: IndexedSetAssignment) {
+    visit(node.target)
+    append("[")
+    visit(node.index)
+    append("]")
+    append(" = ")
+    visit(node.value)
+  }
+
   override fun visitCompilationUnit(node: CompilationUnit) {
     for (declaration in node.declarations) {
       visit(declaration)
diff --git a/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/IndexedSetAssignmentElement.kt b/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/IndexedSetAssignmentElement.kt
new file mode 100644
index 0000000..a61c29d
--- /dev/null
+++ b/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/IndexedSetAssignmentElement.kt
@@ -0,0 +1,15 @@
+// GENERATED CODE FROM PORK AST CODEGEN
+package gay.pizza.pork.idea.psi.gen
+
+import com.intellij.lang.ASTNode
+import com.intellij.navigation.ItemPresentation
+import gay.pizza.pork.idea.psi.PorkElementHelpers
+import javax.swing.Icon
+
+class IndexedSetAssignmentElement(node: ASTNode) : PorkElement(node) {
+  override fun getIcon(flags: Int): Icon? =
+    PorkElementHelpers.iconOf(this)
+
+  override fun getPresentation(): ItemPresentation? =
+    PorkElementHelpers.presentationOf(this)
+}
diff --git a/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/PorkElementFactory.kt b/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/PorkElementFactory.kt
index 6571539..0af4946 100644
--- a/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/PorkElementFactory.kt
+++ b/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/PorkElementFactory.kt
@@ -16,7 +16,8 @@ object PorkElementFactory {
       NodeType.CompilationUnit -> CompilationUnitElement(node)
       NodeType.LetAssignment -> LetAssignmentElement(node)
       NodeType.VarAssignment -> VarAssignmentElement(node)
-      NodeType.SetAssignment -> SetAssignmentElement(node)
+      NodeType.SymbolSetAssignment -> SymbolSetAssignmentElement(node)
+      NodeType.IndexedSetAssignment -> IndexedSetAssignmentElement(node)
       NodeType.InfixOperation -> InfixOperationElement(node)
       NodeType.BooleanLiteral -> BooleanLiteralElement(node)
       NodeType.FunctionCall -> FunctionCallElement(node)
diff --git a/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/SetAssignmentElement.kt b/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/SymbolSetAssignmentElement.kt
similarity index 85%
rename from support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/SetAssignmentElement.kt
rename to support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/SymbolSetAssignmentElement.kt
index 66d62ad..aca6e0a 100644
--- a/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/SetAssignmentElement.kt
+++ b/support/pork-idea/src/main/kotlin/gay/pizza/pork/idea/psi/gen/SymbolSetAssignmentElement.kt
@@ -6,7 +6,7 @@ import com.intellij.navigation.ItemPresentation
 import gay.pizza.pork.idea.psi.PorkElementHelpers
 import javax.swing.Icon
 
-class SetAssignmentElement(node: ASTNode) : PorkElement(node) {
+class SymbolSetAssignmentElement(node: ASTNode) : PorkElement(node) {
   override fun getIcon(flags: Int): Icon? =
     PorkElementHelpers.iconOf(this)
 
diff --git a/vm/src/main/kotlin/gay/pizza/pork/vm/StandardOpHandlers.kt b/vm/src/main/kotlin/gay/pizza/pork/vm/StandardOpHandlers.kt
index 217b7f4..3a90f04 100644
--- a/vm/src/main/kotlin/gay/pizza/pork/vm/StandardOpHandlers.kt
+++ b/vm/src/main/kotlin/gay/pizza/pork/vm/StandardOpHandlers.kt
@@ -15,6 +15,7 @@ val StandardOpHandlers: List<OpHandler> = listOf(
   ListSizeOpHandler,
 
   IndexOpHandler,
+  IndexSetOpHandler,
 
   AndOpHandler,
   OrOpHandler,
diff --git a/vm/src/main/kotlin/gay/pizza/pork/vm/ops/IndexSetOpHandler.kt b/vm/src/main/kotlin/gay/pizza/pork/vm/ops/IndexSetOpHandler.kt
new file mode 100644
index 0000000..b1c2b41
--- /dev/null
+++ b/vm/src/main/kotlin/gay/pizza/pork/vm/ops/IndexSetOpHandler.kt
@@ -0,0 +1,15 @@
+package gay.pizza.pork.vm.ops
+
+import gay.pizza.pork.bytecode.Op
+import gay.pizza.pork.bytecode.Opcode
+import gay.pizza.pork.vm.InternalMachine
+import gay.pizza.pork.vm.OpHandler
+
+object IndexSetOpHandler : OpHandler(Opcode.IndexSet) {
+  override fun handle(machine: InternalMachine, op: Op) {
+    val list = machine.pop<MutableList<Any>>()
+    val index = machine.pop<Number>().toInt()
+    val value = machine.pop<Any>()
+    list[index] = value
+  }
+}
diff --git a/vm/src/main/kotlin/gay/pizza/pork/vm/ops/ListMakeOpHandler.kt b/vm/src/main/kotlin/gay/pizza/pork/vm/ops/ListMakeOpHandler.kt
index 0983429..2b6ab05 100644
--- a/vm/src/main/kotlin/gay/pizza/pork/vm/ops/ListMakeOpHandler.kt
+++ b/vm/src/main/kotlin/gay/pizza/pork/vm/ops/ListMakeOpHandler.kt
@@ -13,6 +13,6 @@ object ListMakeOpHandler : OpHandler(Opcode.ListMake) {
       val item = machine.popAnyValue()
       list.add(item)
     }
-    machine.push(list.reversed())
+    machine.push(list.reversed().toMutableList())
   }
 }