diff --git a/src/cc65/coptstop.c b/src/cc65/coptstop.c
index 8b2821dcd..ae40a55e9 100644
--- a/src/cc65/coptstop.c
+++ b/src/cc65/coptstop.c
@@ -1208,6 +1208,8 @@ static unsigned Opt_a_tosicmp (StackOpData* D)
             /* RHS src is not directly comparable */
             X = NewCodeEntry (OP65_STA, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);
             InsertEntry (D, X, D->Rhs.A.ChgIndex + 1);
+            /* RHS insertion may have moved the OpIndex, recalculate insertion point to prevent label migration. */
+            D->IP = D->OpIndex + 1;
 
             /* Cmp with stored RHS */
             X = NewCodeEntry (OP65_CMP, AM65_ZP, D->ZPHi, 0, D->OpEntry->LI);