diff --git a/compiler/src/prog8/ast/expressions/AstExpressions.kt b/compiler/src/prog8/ast/expressions/AstExpressions.kt
index 89d4d7dc2..9f2200adf 100644
--- a/compiler/src/prog8/ast/expressions/AstExpressions.kt
+++ b/compiler/src/prog8/ast/expressions/AstExpressions.kt
@@ -407,10 +407,14 @@ class StructLiteralValue(var values: List<Expression>,
     }
 }
 
+private var heapIdSequence = 0   // unique ids for strings and arrays "on the heap"
+
 class StringLiteralValue(val value: String,
                          override val position: Position) : Expression() {
     override lateinit var parent: Node
 
+    val heapId = ++heapIdSequence
+
     override fun linkParents(parent: Node) {
         this.parent = parent
     }
@@ -427,19 +431,8 @@ class StringLiteralValue(val value: String,
             return false
         return value==other.value
     }
-
-    var heapId: Int? = null
-        private set
-
-    fun addToHeap() {
-        if(heapId==null)
-            heapId = ++heapIdSequence
-    }
 }
 
-private var heapIdSequence = 0
-
-
 class ArrayLiteralValue(val type: DataType,     // only array types
                         val value: Array<Expression>,
                         initHeapId: Int? =null,
@@ -648,7 +641,7 @@ data class IdentifierReference(val nameInSource: List<String>, override val posi
         val value = (node as? VarDecl)?.value ?: throw FatalAstException("requires a reference value")
         return when (value) {
             is IdentifierReference -> value.heapId(namespace)
-            is StringLiteralValue -> value.heapId ?: throw FatalAstException("string is not on the heap: $value")
+            is StringLiteralValue -> value.heapId
             is ArrayLiteralValue -> value.heapId ?: throw FatalAstException("array is not on the heap: $value")
             else -> throw FatalAstException("requires a reference value")
         }
diff --git a/compiler/src/prog8/ast/processing/AstChecker.kt b/compiler/src/prog8/ast/processing/AstChecker.kt
index ee1f334a5..a8d546086 100644
--- a/compiler/src/prog8/ast/processing/AstChecker.kt
+++ b/compiler/src/prog8/ast/processing/AstChecker.kt
@@ -702,8 +702,6 @@ internal class AstChecker(private val program: Program,
     override fun visit(string: StringLiteralValue) {
         checkValueTypeAndRangeString(DataType.STR, string)
         super.visit(string)
-        if(string.heapId==null)
-            throw FatalAstException("string should have been moved to heap at ${string.position}")
     }
 
     override fun visit(expr: PrefixExpression) {
diff --git a/compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt b/compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt
index 5e0876d24..f7567eddf 100644
--- a/compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt
+++ b/compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt
@@ -253,9 +253,6 @@ internal class AstIdentifiersChecker(private val program: Program) : IAstModifyi
             // intern the string; move it into the heap
             if (string.value.length !in 1..255)
                 checkResult.add(ExpressionError("string literal length must be between 1 and 255", string.position))
-            else {
-                string.addToHeap()
-            }
             return if (vardecl != null)
                 string
             else
@@ -292,7 +289,6 @@ internal class AstIdentifiersChecker(private val program: Program) : IAstModifyi
         // a referencetype literal value that's not declared as a variable
         // we need to introduce an auto-generated variable for this to be able to refer to the value
         // note: if the var references the same literal value, it is not yet de-duplicated here.
-        string.addToHeap()
         val scope = string.definingScope()
         val variable = VarDecl.createAuto(string)
         return replaceWithIdentifier(variable, scope, string.parent)
diff --git a/compiler/src/prog8/ast/statements/AstStatements.kt b/compiler/src/prog8/ast/statements/AstStatements.kt
index 49c0ed953..48963d4d0 100644
--- a/compiler/src/prog8/ast/statements/AstStatements.kt
+++ b/compiler/src/prog8/ast/statements/AstStatements.kt
@@ -192,8 +192,6 @@ class VarDecl(val type: VarDeclType,
         private var autoHeapValueSequenceNumber = 0
 
         fun createAuto(string: StringLiteralValue): VarDecl {
-            if(string.heapId==null)
-                throw FatalAstException("can only create autovar for a string that has a heapid  $string")
             val autoVarName = "auto_heap_value_${++autoHeapValueSequenceNumber}"
             return VarDecl(VarDeclType.VAR, DataType.STR, ZeropageWish.NOT_IN_ZEROPAGE, null, autoVarName, null, string,
                         isArray = false, autogeneratedDontRemove = true, position = string.position)
diff --git a/compiler/src/prog8/optimizer/ConstantFolding.kt b/compiler/src/prog8/optimizer/ConstantFolding.kt
index c8e07fab2..e991bee42 100644
--- a/compiler/src/prog8/optimizer/ConstantFolding.kt
+++ b/compiler/src/prog8/optimizer/ConstantFolding.kt
@@ -146,19 +146,6 @@ class ConstantFolding(private val program: Program) : IAstModifyingVisitor {
                         }
                     }
                 }
-                DataType.STR -> {
-                    TODO("$decl")
-//                    if(functionCall.target.nameInSource == listOf("c64scr")) {
-//                        val parent = functionCall.parent
-//                        if(parent is VarDecl && parent.datatype==DataType.STR && functionCall.args.size == 1) {
-//                            val str = functionCall.args[0] as IdentifierReference
-//                            if(str!=null) {
-//                                val decl = str.targetVarDecl(functionCall.definingScope())
-//                                TODO("$decl")
-//                            }
-//                        }
-//                    }
-                }
                 else -> {
                     // nothing to do for this type
                     // this includes strings and structs
diff --git a/compiler/src/prog8/vm/RuntimeValue.kt b/compiler/src/prog8/vm/RuntimeValue.kt
index bdbce0912..b7098af23 100644
--- a/compiler/src/prog8/vm/RuntimeValue.kt
+++ b/compiler/src/prog8/vm/RuntimeValue.kt
@@ -573,7 +573,7 @@ class RuntimeValueNumeric(type: DataType, num: Number): RuntimeValueBase(type) {
 class RuntimeValueString(val str: String, val heapId: Int?): RuntimeValueBase(DataType.STR) {
     companion object {
         fun fromLv(string: StringLiteralValue): RuntimeValueString {
-            return RuntimeValueString(string.value, string.heapId!!)
+            return RuntimeValueString(string.value, string.heapId)
         }
     }