diff --git a/compiler/src/prog8/compiler/target/cx16/CX16MachineDefinition.kt b/compiler/src/prog8/compiler/target/cx16/CX16MachineDefinition.kt
index 1828d5865..c1d92da94 100644
--- a/compiler/src/prog8/compiler/target/cx16/CX16MachineDefinition.kt
+++ b/compiler/src/prog8/compiler/target/cx16/CX16MachineDefinition.kt
@@ -71,8 +71,8 @@ internal object CX16MachineDefinition: IMachineDefinition {
 
     internal class CX16Zeropage(options: CompilationOptions) : Zeropage(options) {
 
-        override val SCRATCH_B1 = 0x79      // temp storage for a single byte
-        override val SCRATCH_REG = 0x7a     // temp storage for a register, must be B1+1
+        override val SCRATCH_B1 = 0x7a      // temp storage for a single byte
+        override val SCRATCH_REG = 0x7b     // temp storage for a register, must be B1+1
         override val SCRATCH_W1 = 0x7c      // temp storage 1 for a word  $7c+$7d
         override val SCRATCH_W2 = 0x7e      // temp storage 2 for a word  $7e+$7f