diff --git a/backend_wat.go b/backend_wat.go
index 2204128..8370115 100644
--- a/backend_wat.go
+++ b/backend_wat.go
@@ -91,6 +91,14 @@ func (c *Compiler) getAddressWATType() string {
 	}
 }
 
+func (c *Compiler) getEffectiveAddressType() PrimitiveType {
+	if c.Wasm64 {
+		return Primitive_U64
+	} else {
+		return Primitive_U32
+	}
+}
+
 func (c *Compiler) getWATType(t Type) string {
 	switch t.Type {
 	case Type_Primitive:
@@ -212,6 +220,83 @@ func (c *Compiler) compileAssignmentExpressionWAT(assignment AssignmentExpressio
 	panic("assignment expr not implemented")
 }
 
+func (c *Compiler) compileAssignmentUpdateExpressionWAT(lhs Expression, updateWAT string, evaluateToOldValue bool) (string, error) {
+	switch lhs.Type {
+	case Expression_VariableReference:
+		ref := lhs.Value.(VariableReferenceExpression)
+		local := strconv.Itoa(getLocal(c.CurrentBlock, ref.Variable).Index)
+
+		exprWAT, err := c.compileExpressionWAT(lhs)
+		if err != nil {
+			return "", err
+		}
+
+		var tmpLocal Local
+		wat := exprWAT
+		if evaluateToOldValue {
+			tmpLocal = Local{Name: "", Type: *lhs.ValueType, IsParameter: false, Index: len(c.CurrentFunction.Locals)}
+			c.CurrentFunction.Locals = append(c.CurrentFunction.Locals, tmpLocal)
+
+			wat += "local.tee $" + strconv.Itoa(tmpLocal.Index) + "\n"
+		}
+
+		wat += updateWAT
+
+		if evaluateToOldValue {
+			wat += "local.set $" + local + "\n"
+			wat += "local.get $" + strconv.Itoa(tmpLocal.Index) + "\n"
+		} else {
+			wat += "local.tee $" + local + "\n"
+		}
+
+		return wat, nil
+	case Expression_ArrayAccess:
+		panic("TODO") // TODO
+	case Expression_RawMemoryReference:
+		raw := lhs.Value.(RawMemoryReferenceExpression)
+
+		localAddress := Local{Name: "", Type: Type{Type: Type_Primitive, Value: c.getEffectiveAddressType()}, IsParameter: false, Index: len(c.CurrentFunction.Locals)}
+		c.CurrentFunction.Locals = append(c.CurrentFunction.Locals, localAddress)
+
+		localValue := Local{Name: "", Type: *lhs.ValueType, IsParameter: false, Index: len(c.CurrentFunction.Locals)}
+		c.CurrentFunction.Locals = append(c.CurrentFunction.Locals, localValue)
+
+		if raw.Type.Type != Type_Primitive {
+			panic("TODO") //TODO
+		}
+
+		addrWAT, err := c.compileExpressionWAT(raw.Address)
+		if err != nil {
+			return "", err
+		}
+
+		wat := addrWAT
+
+		// dup address
+		wat += "local.tee $" + strconv.Itoa(localAddress.Index) + "\n"
+		wat += "local.get $" + strconv.Itoa(localAddress.Index) + "\n"
+
+		wat += c.getWATType(raw.Type) + ".load\n"
+
+		if evaluateToOldValue {
+			wat += "local.tee $" + strconv.Itoa(localValue.Index) + "\n"
+		}
+
+		wat += updateWAT
+
+		if !evaluateToOldValue {
+			wat += "local.tee $" + strconv.Itoa(localValue.Index) + "\n"
+		}
+
+		wat += c.getWATType(raw.Type) + ".store\n"
+		wat += "local.get $" + strconv.Itoa(localValue.Index) + "\n"
+
+		return wat, nil
+	}
+
+	panic("assignment expr not implemented")
+}
+
 func (c *Compiler) compileExpressionWAT(expr Expression) (string, error) {
 	var err error
 
@@ -351,7 +436,16 @@ func (c *Compiler) compileExpressionWAT(expr Expression) (string, error) {
 		case UnaryOperation_LogicalNot:
 			return wat + "i32.eqz\n", nil
 		case UnaryOperation_PreIncrement, UnaryOperation_PreDecrement, UnaryOperation_PostIncrement, UnaryOperation_PostDecrement:
-			// TODO: implement
+			valueType := c.getWATType(*unary.Value.ValueType)
+
+			updateWAT := valueType + ".const 1\n"
+			if unary.Operation == UnaryOperation_PreIncrement || unary.Operation == UnaryOperation_PostIncrement {
+				updateWAT += valueType + ".add\n"
+			} else {
+				updateWAT += valueType + ".sub\n"
+			}
+
+			return c.compileAssignmentUpdateExpressionWAT(unary.Value, updateWAT, unary.Operation == UnaryOperation_PostIncrement || unary.Operation == UnaryOperation_PostDecrement)
 		}
 	case Expression_Cast:
 		cast := expr.Value.(CastExpression)
@@ -379,7 +473,7 @@ func (c *Compiler) compileExpressionWAT(expr Expression) (string, error) {
 		}
 
 		if raw.Type.Type == Type_Primitive {
-			wat += c.getWATType(raw.Type) + ".load\n"
+			wat += c.getWATType(raw.Type) + ".load\n" // TODO: use load8/load16(_s/u) for smaller types
 		}
 
 		return wat, nil
diff --git a/example/test.ely b/example/test.ely
index 14635b7..a1653bb 100644
--- a/example/test.ely
+++ b/example/test.ely
@@ -20,3 +20,16 @@ u64 fib(u64 i) {
 
 	return fibA;
 }
+
+(u64, u64) add(u64 a) {
+	u64 x = a++;
+	return x, a;
+}
+
+(u64, u64) tuple() {
+	return 1u64, 2u64;
+}
+
+u64 sub(u64 a) {
+	return --raw(u64, 0xFFu64);
+}
diff --git a/main.go b/main.go
index e80b138..6befef9 100644
--- a/main.go
+++ b/main.go
@@ -151,7 +151,7 @@ func main() {
 		parsedFiles = append(parsedFiles, parsed)
 	}
 
-	validator := Validator{Files: parsedFiles}
+	validator := Validator{Files: parsedFiles, Wasm64: *wasm64}
 	errors := validator.validate()
 	if len(errors) != 0 {
 		for _, err := range errors {
@@ -188,7 +188,14 @@ func main() {
 		return
 	}
 
-	cmd := exec.Command("wat2wasm", "-o", *outputFile, "-")
+	var command []string
+	if *wasm64 {
+		// TODO: wasm64 support is currently broken because x.load doesn't accept 64-bit addresses
+		command = append(command, "--enable-memory64")
+	}
+	command = append(command, "-o", *outputFile, "-")
+
+	cmd := exec.Command("wat2wasm", command...)
 
 	var input bytes.Buffer
 	input.Write([]byte(wat))