diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index c78f335fa981..f2c5e7910bb1 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -302,7 +302,11 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 		} else {
 			for (end = buf; *end && !isspace(*end); end++)
 				;
-			BUG_ON(end == buf);
+			if (end == buf) {
+				pr_err("parse err after word:%d=%s\n", nwords,
+				       nwords ? words[nwords - 1] : "<none>");
+				return -EINVAL;
+			}
 		}
 
 		/* `buf' is start of word, `end' is one past its end */