diff --git a/Fonderie/crapulator.c b/Fonderie/crapulator.c
index 4a5af6b..e0175e4 100644
--- a/Fonderie/crapulator.c
+++ b/Fonderie/crapulator.c
@@ -514,6 +514,11 @@ switch (idFx) {
 		retval = fimg_to_gray(image);
 		break;
 
+	case CR_shift0:
+		/* added Sun Sep 29 16:55:54 UTC 2024 */
+		retval = fimg_auto_shift_to_zero(image, image);
+		// fprintf(stderr, "******** Shift Zero -> %d\n", retval);
+		break;
 
 	default :
 		fprintf(stderr, "%s : effect #%d invalid\n", 
diff --git a/Fonderie/crapulors.liste b/Fonderie/crapulors.liste
index 1674565..0dba7dd 100644
--- a/Fonderie/crapulors.liste
+++ b/Fonderie/crapulors.liste
@@ -47,5 +47,6 @@
 80	thermocol	1	0
 81	triptyq		1	0
 90	togray		1	0
+91	shift0		1	0
 -1	end		1	1.0