diff --git a/libsrc/c64/acc_c65_speed.s b/libsrc/c64/acc_c65_speed.s
index 94fa50e91..1c218f0b5 100755
--- a/libsrc/c64/acc_c65_speed.s
+++ b/libsrc/c64/acc_c65_speed.s
@@ -54,7 +54,7 @@ _get_c65_speed:
 return_c65_speed:
         sta     C65_VICIII_KEY
         and     #$40
-        beq     speed_is_slow
+        beq     speed_is_slow              ; when this branch is taken then register A is already set to SPEED_SLOW
         lda     #SPEED_3X
         .byte   $2C
 speed_is_slow: