diff --git a/c64/kernal/iec_release_clk.s b/c64/kernal/iec_release_clk.s
index cf12e8c0..a261ee4d 100644
--- a/c64/kernal/iec_release_clk.s
+++ b/c64/kernal/iec_release_clk.s
@@ -1,5 +1,5 @@
 iec_release_clk:
 	lda $dd00
-	and #$1b
+	and #$2b
 	sta $dd00
 	rts