diff --git a/compiler/src/prog8/compiler/target/c64/codegen/ExpressionsAsmGen.kt b/compiler/src/prog8/compiler/target/c64/codegen/ExpressionsAsmGen.kt
index 5d159bcbf..35557b8ed 100644
--- a/compiler/src/prog8/compiler/target/c64/codegen/ExpressionsAsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/codegen/ExpressionsAsmGen.kt
@@ -22,7 +22,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
             is DirectMemoryRead -> translateDirectMemReadExpression(expression, true)
             is NumericLiteralValue -> translateExpression(expression)
             is IdentifierReference -> translateExpression(expression)
-            is FunctionCall -> translateExpression(expression)
+            is FunctionCall -> translateFunctionCallResultOntoStack(expression)
             is ArrayLiteralValue, is StringLiteralValue -> throw AssemblyError("no asm gen for string/array literal value assignment - should have been replaced by a variable")
             is RangeExpr -> throw AssemblyError("range expression should have been changed into array values")
         }
@@ -942,7 +942,7 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
         asmgen.out("  jsr  floats.notequal_f |  inx |  lda  P8ESTACK_LO,x |  beq  $jumpIfFalseLabel")
     }
 
-    private fun translateExpression(expression: FunctionCall) {
+    private fun translateFunctionCallResultOntoStack(expression: FunctionCall) {
         val functionName = expression.target.nameInSource.last()
         val builtinFunc = BuiltinFunctions[functionName]
         if (builtinFunc != null) {
diff --git a/compiler/src/prog8/compiler/target/c64/codegen/assignment/AssignmentAsmGen.kt b/compiler/src/prog8/compiler/target/c64/codegen/assignment/AssignmentAsmGen.kt
index 9dd64d183..88c381efc 100644
--- a/compiler/src/prog8/compiler/target/c64/codegen/assignment/AssignmentAsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/codegen/assignment/AssignmentAsmGen.kt
@@ -125,14 +125,18 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                     is TypecastExpression -> assignTypeCastedValue(assign.target, value.type, value.expression, assign)
                     is FunctionCall -> {
                         if(value.target.targetSubroutine(program.namespace)?.isAsmSubroutine==true) {
-                            // TODO handle asmsub functioncalls specifically, without shoving stuff on the estack
-                            asmgen.translateExpression(value)
-                            assignStackValue(assign.target)
-                            val sub = value.target.targetSubroutine(program.namespace)
-                            if(sub!=null && sub.asmReturnvaluesRegisters.any { it.statusflag != null }) {
-                                // the expression translation will have generated a 'php' instruction earlier.
-                                asmgen.out("  plp\t; restore status flags from call")
+                            // handle asmsub functioncalls specifically, without shoving stuff on the estack
+                            val sub = value.target.targetSubroutine(program.namespace)!!
+                            val preserveStatusRegisterAfterCall = sub.asmReturnvaluesRegisters.any { it.statusflag != null }
+                            asmgen.translateFunctionCall(value, preserveStatusRegisterAfterCall)
+                            when((sub.asmReturnvaluesRegisters.single { it.registerOrPair!=null }).registerOrPair) {
+                                RegisterOrPair.A -> assignRegisterByte(assign.target, CpuRegister.A)
+                                RegisterOrPair.X -> assignRegisterByte(assign.target, CpuRegister.X)
+                                RegisterOrPair.Y -> assignRegisterByte(assign.target, CpuRegister.Y)
+                                else -> throw AssemblyError("should be just one register byte result value")
                             }
+                            if(preserveStatusRegisterAfterCall)
+                                asmgen.out("  plp\t; restore status flags from call")
                         } else {
                             // regular subroutine, return values are (for now) always done via the stack...  TODO optimize this
                             asmgen.translateExpression(value)
diff --git a/examples/test.p8 b/examples/test.p8
index 891937b54..14f7fcd97 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -18,12 +18,13 @@ main {
             return
 
 
-;        ; TODO make this work as well, with the same warning:
-;        ubyte status2 = c64.OPEN()          ; open 1,8,0,"$"
+        ; TODO make this work as well, with the same warning:
+        ubyte status2 = c64.OPEN()          ; open 1,8,0,"$"
         if_cs
             return
 
-
+        txt.print_ub(status)
+        txt.print_ub(status2)
 
         txt.print(planet_name)
         txt.chrout('\n')