diff --git a/bin/sh/alias.c b/bin/sh/alias.c
--- a/bin/sh/alias.c
+++ b/bin/sh/alias.c
@@ -204,6 +204,11 @@
 		return (0);
 	}
 	while ((n = *argptr++) != NULL) {
+		if (n[0] == '\0') {
+			warning("'': not found");
+			ret = 1;
+			continue;
+		}
 		if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */
 			if ((ap = lookupalias(n, 0)) == NULL) {
 				warning("%s: not found", n);