diff --git a/src/datasets.c b/src/datasets.c
index e82bed27ad..bce22f3c1c 100644
--- a/src/datasets.c
+++ b/src/datasets.c
@@ -248,7 +248,7 @@ static int DatasetLoadIPv4(Dataset *set)
 static int ParseIpv6String(Dataset *set, const char *line, struct in6_addr *in6)
 {
     /* Checking IPv6 case */
-    char *got_colon = strchr(line, ':');
+    const char *got_colon = strchr(line, ':');
     if (got_colon) {
         uint32_t ip6addr[4];
         if (inet_pton(AF_INET6, line, in6) != 1) {