diff --git a/src/util-strings.c b/src/util-strings.c
index 41c1d95..6e6140a 100644
--- a/src/util-strings.c
+++ b/src/util-strings.c
@@ -150,11 +150,17 @@ strv_join(char **strv, const char *joiner)
 	slen += (count - 1) * strlen(joiner);
 
 	str = xalloc(slen + 1); /* trailing \0 */
+	size_t jlen = strlen(joiner);
+	size_t offset = 0;
 	for (s = strv; *s; s++) {
-		strcat(str, *s);
+		size_t l = strlen(*s);
+		memcpy(str + offset, *s, l);
+		offset += l;
 		--count;
-		if (count > 0)
-			strcat(str, joiner);
+		if (count > 0) {
+			memcpy(str + offset, joiner, jlen);
+			offset += jlen;
+		}
 	}
 
 	return str;