diff --git a/util/ego/cs/cs_debug.c b/util/ego/cs/cs_debug.c
index 3d5509ddc..8cc626ea3 100644
--- a/util/ego/cs/cs_debug.c
+++ b/util/ego/cs/cs_debug.c
@@ -24,7 +24,7 @@ STATIC void showinstr(line_p lnp)
 	 * can occur in expressions that are going to be eliminated are
 	 * properly handled.
 	 */
-	if (INSTR(lnp) < sp_fmnem && INSTR(lnp) > sp_lmnem) {
+	if (INSTR(lnp) < sp_fmnem || INSTR(lnp) > sp_lmnem) {
 		fprintf(stderr,"*** ?\n");
 		return;
 	}