diff --git a/compiler/res/version.txt b/compiler/res/version.txt
index d456f7459..853262655 100644
--- a/compiler/res/version.txt
+++ b/compiler/res/version.txt
@@ -1 +1 @@
-1.80
+1.81-SNAPSHOT
diff --git a/compiler/src/prog8/compiler/target/IAssemblyGenerator.kt b/compiler/src/prog8/compiler/target/IAssemblyGenerator.kt
index e050d27fe..50992f2ce 100644
--- a/compiler/src/prog8/compiler/target/IAssemblyGenerator.kt
+++ b/compiler/src/prog8/compiler/target/IAssemblyGenerator.kt
@@ -6,6 +6,8 @@ internal interface IAssemblyGenerator {
     fun compileToAssembly(optimize: Boolean): IAssemblyProgram
 }
 
+internal const val generatedLabelPrefix = "_prog8_label_"
+
 internal interface IAssemblyProgram {
     val name: String
     fun assemble(options: CompilationOptions)
diff --git a/compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt b/compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt
index 08ce35de0..d4659d52a 100644
--- a/compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt
+++ b/compiler/src/prog8/compiler/target/c64/AssemblyProgram.kt
@@ -3,10 +3,11 @@ package prog8.compiler.target.c64
 import prog8.compiler.CompilationOptions
 import prog8.compiler.OutputType
 import prog8.compiler.target.IAssemblyProgram
+import prog8.compiler.target.generatedLabelPrefix
 import java.nio.file.Path
 import kotlin.system.exitProcess
 
-class AssemblyProgram(override val name: String, outputDir: Path): IAssemblyProgram {
+class AssemblyProgram(override val name: String, outputDir: Path) : IAssemblyProgram {
     private val assemblyFile = outputDir.resolve("$name.asm")
     private val prgFile = outputDir.resolve("$name.prg")
     private val binFile = outputDir.resolve("$name.bin")
@@ -18,7 +19,7 @@ class AssemblyProgram(override val name: String, outputDir: Path): IAssemblyProg
                 "-Wall", "-Wno-strict-bool", "-Wno-shadow", "-Werror", "-Wno-error=long-branch",
                 "--dump-labels", "--vice-labels", "-l", viceMonListFile.toString(), "--no-monitor")
 
-        val outFile = when(options.output) {
+        val outFile = when (options.output) {
             OutputType.PRG -> {
                 command.add("--cbm-prg")
                 println("\nCreating C-64 prg.")
@@ -34,27 +35,39 @@ class AssemblyProgram(override val name: String, outputDir: Path): IAssemblyProg
 
         val proc = ProcessBuilder(command).inheritIO().start()
         val result = proc.waitFor()
-        if(result!=0) {
+        if (result != 0) {
             System.err.println("assembler failed with returncode $result")
             exitProcess(result)
         }
 
+        removeGeneratedLabelsFromMonlist()
         generateBreakpointList()
     }
 
+    private fun removeGeneratedLabelsFromMonlist() {
+        val pattern = Regex("""al (\w+) \S+${generatedLabelPrefix}.+?""")
+        val lines = viceMonListFile.toFile().readLines()
+        viceMonListFile.toFile().outputStream().bufferedWriter().use {
+            for (line in lines) {
+                if(pattern.matchEntire(line)==null)
+                    it.write(line+"\n")
+            }
+        }
+    }
+
     private fun generateBreakpointList() {
         // builds list of breakpoints, appends to monitor list file
         val breakpoints = mutableListOf<String>()
-        val pattern = Regex("""al (\w+) \S+_prog8_breakpoint_\d+.?""")      // gather breakpoints by the source label that"s generated for them
-        for(line in viceMonListFile.toFile().readLines()) {
+        val pattern = Regex("""al (\w+) \S+_prog8_breakpoint_\d+.?""")      // gather breakpoints by the source label that's generated for them
+        for (line in viceMonListFile.toFile().readLines()) {
             val match = pattern.matchEntire(line)
-            if(match!=null)
-            breakpoints.add("break \$" + match.groupValues[1])
+            if (match != null)
+                breakpoints.add("break \$" + match.groupValues[1])
         }
         val num = breakpoints.size
         breakpoints.add(0, "; vice monitor breakpoint list now follows")
         breakpoints.add(1, "; $num breakpoints have been defined")
         breakpoints.add(2, "del")
-        viceMonListFile.toFile().appendText(breakpoints.joinToString("\n")+"\n")
+        viceMonListFile.toFile().appendText(breakpoints.joinToString("\n") + "\n")
     }
 }
diff --git a/compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt b/compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt
index 829c97ae7..5c9ba0e26 100644
--- a/compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt
@@ -14,6 +14,7 @@ import prog8.compiler.target.c64.C64MachineDefinition
 import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_LO_HEX
 import prog8.compiler.target.c64.C64MachineDefinition.ESTACK_HI_HEX
 import prog8.compiler.target.c64.Petscii
+import prog8.compiler.target.generatedLabelPrefix
 import prog8.functions.BuiltinFunctions
 import prog8.functions.FunctionSignature
 import java.math.RoundingMode
@@ -178,7 +179,7 @@ internal class AsmGen(private val program: Program,
 
     internal fun makeLabel(postfix: String): String {
         generatedLabelSequenceNumber++
-        return "_prog8_label_${generatedLabelSequenceNumber}_$postfix"
+        return "${generatedLabelPrefix}${generatedLabelSequenceNumber}_$postfix"
     }
 
     private fun outputSourceLine(node: Node) {