diff --git a/src/quirks.c b/src/quirks.c
index 75c74c0b..2bb37b4f 100644
--- a/src/quirks.c
+++ b/src/quirks.c
@@ -1314,7 +1314,7 @@ match_fill_uniq(struct match *m,
 		str++;
 
 	m->uniq = safe_strdup(str);
-	slen = strlen(m->uniq);
+	slen = safe_strlen(m->uniq);
 	if (slen > 1 &&
 	    m->uniq[slen - 1] == '"')
 		m->uniq[slen - 1] = '\0';
diff --git a/src/util-strings.h b/src/util-strings.h
index 85e9081d..bc263f6c 100644
--- a/src/util-strings.h
+++ b/src/util-strings.h
@@ -99,6 +99,15 @@ safe_strdup(const char *str)
 	return s;
 }
 
+/**
+ * NULL-safe version of strlen
+ */
+static inline size_t
+safe_strlen(const char *str)
+{
+	return str ? strlen(str) : 0;
+}
+
 /**
  * Simple wrapper for asprintf that ensures the passed in-pointer is set
  * to NULL upon error.