diff --git a/compiler/res/prog8lib/c64utils.p8 b/compiler/res/prog8lib/c64utils.p8
index 113721afa..ad343f150 100644
--- a/compiler/res/prog8lib/c64utils.p8
+++ b/compiler/res/prog8lib/c64utils.p8
@@ -1063,7 +1063,7 @@ _mod		lda  $ffff		; modified
 sub  setcc  (ubyte column, ubyte row, ubyte char, ubyte color)  {
 	; ---- set char+color at the given position on the screen
 	%asm {{
-		lda  setcc_row
+		lda  row
 		asl  a
 		tay
 		lda  setchr._screenrows+1,y
@@ -1072,15 +1072,15 @@ sub  setcc  (ubyte column, ubyte row, ubyte char, ubyte color)  {
 		sta  _colormod+2
 		lda  setchr._screenrows,y
 		clc
-		adc  setcc_column
+		adc  column
 		sta  _charmod+1
 		sta  _colormod+1
 		bcc  +
 		inc  _charmod+2
 		inc  _colormod+2
-+		lda  setcc_char
++		lda  char
 _charmod	sta  $ffff		; modified
-		lda  setcc_color
+		lda  color
 _colormod	sta  $ffff		; modified
 		rts
 	}}
diff --git a/compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt b/compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt
index 0779c567b..eeaced4a5 100644
--- a/compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt
+++ b/compiler/src/prog8/ast/processing/AstIdentifiersChecker.kt
@@ -67,8 +67,6 @@ internal class AstIdentifiersChecker(private val program: Program) : IAstModifyi
             // the builtin functions can't be redefined
             checkResult.add(NameError("builtin function cannot be redefined", decl.position))
 
-        if(decl.name in AssemblyProgram.reservedNames)
-            checkResult.add(NameError("can't use a symbol name reserved by the assembler program", decl.position))
         if(decl.name in AssemblyProgram.opcodeNames)
             checkResult.add(NameError("can't use a cpu opcode name as a symbol", decl.position))
 
@@ -106,7 +104,9 @@ internal class AstIdentifiersChecker(private val program: Program) : IAstModifyi
     }
 
     override fun visit(subroutine: Subroutine): Statement {
-        if(subroutine.name in BuiltinFunctions) {
+        if(subroutine.name in AssemblyProgram.opcodeNames) {
+            checkResult.add(NameError("can't use a cpu opcode name as a symbol", subroutine.position))
+        } else if(subroutine.name in BuiltinFunctions) {
             // the builtin functions can't be redefined
             checkResult.add(NameError("builtin function cannot be redefined", subroutine.position))
         } else {
@@ -162,6 +162,9 @@ internal class AstIdentifiersChecker(private val program: Program) : IAstModifyi
     }
 
     override fun visit(label: Label): Statement {
+        if(label.name in AssemblyProgram.opcodeNames)
+            checkResult.add(NameError("can't use a cpu opcode name as a symbol", label.position))
+
         if(label.name in BuiltinFunctions) {
             // the builtin functions can't be redefined
             checkResult.add(NameError("builtin function cannot be redefined", label.position))
diff --git a/compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt b/compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt
index 88c04eea2..d4de7ffcf 100644
--- a/compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt
+++ b/compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt
@@ -10,12 +10,7 @@ class AssemblyProgram(val name: String) {
     private val viceMonListFile = "$name.vice-mon-list"
 
     companion object {
-        // reserved by the 64tass assembler (on top of prog8"s own reserved names)
-        val reservedNames = setOf("bits", "bool", "bytes", "code", "dict", "gap", "int", "list", "tuple", "type",
-                "trunc", " frac", "cbrt", "log10", "log", "exp", "pow", "asin", "sinh", "acos", "cosh", "tanh", "hypot",
-                "atan2", "sign", "binary", "format", "random", "range", "repr", "size", "sort")
-
-        // 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable names either
+        // 6502 opcodes (including aliases and illegal opcodes), these cannot be used as variable or label names
         val opcodeNames = setOf("adc", "ahx", "alr", "anc", "and", "ane", "arr", "asl", "asr", "axs", "bcc", "bcs",
                 "beq", "bge", "bit", "blt", "bmi", "bne", "bpl", "brk", "bvc", "bvs", "clc",
                 "cld", "cli", "clv", "cmp", "cpx", "cpy", "dcm", "dcp", "dec", "dex", "dey",
@@ -30,8 +25,9 @@ class AssemblyProgram(val name: String) {
 
     fun assemble(options: CompilationOptions) {
         // add "-Wlong-branch"  to see warnings about conversion of branch instructions to jumps
-        val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch", "-Wall", "-Wno-strict-bool",
-                "-Werror", "-Wno-error=long-branch", "--dump-labels", "--vice-labels", "-l", viceMonListFile, "--no-monitor")
+        val command = mutableListOf("64tass", "--ascii", "--case-sensitive", "--long-branch",
+                "-Wall", "-Wno-strict-bool", "-Wno-shadow", "-Werror", "-Wno-error=long-branch",
+                "--dump-labels", "--vice-labels", "-l", viceMonListFile, "--no-monitor")
 
         val outFile = when(options.output) {
             OutputType.PRG -> {
diff --git a/examples/test.p8 b/examples/test.p8
index 0191a399f..84365a1be 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -6,7 +6,27 @@
 main {
 
     sub start() {
-        memset(c64.Screen, 40, 1)
-        memset(c64.Screen+40, 80, 2)
+
+        ubyte x=3
+        ubyte y=2
+        ubyte a=1
+        ubyte s=0
+        float repr=4.4
+        ;memset(c64.Screen, 40, 1)
+        ;memset(c64.Screen+40, 80, 2)
+        A=x
+        A=y
+        Y=a
+        A=s
+    }
+
+    sub foo() {
+
+    x:
+    s:
+    y:
+    a:
+        A=3
+
     }
 }