diff --git a/sys/include/net/sock/util.h b/sys/include/net/sock/util.h
index 5b1f443a3df6..fb5d828ea21c 100644
--- a/sys/include/net/sock/util.h
+++ b/sys/include/net/sock/util.h
@@ -54,12 +54,14 @@ int sock_udp_ep_fmt(const sock_udp_ep_t *endpoint, char *addr_str, uint16_t *por
  *
  * @note Caller has to make sure hostport and urlpath can hold the results!
  *       Make sure to provide space for @ref SOCK_HOSTPORT_MAXLEN respectively
- *       @ref SOCK_URLPATH_MAXLEN bytes.
+ *       @ref SOCK_URLPATH_MAXLEN bytes, if pointers are not NULL.
  *       Scheme part of the URL is limited to @ref SOCK_SCHEME_MAXLEN length.
  *
- * @param[in]   url         URL to split
- * @param[out]  hostport    where to write host:port
- * @param[out]  urlpath     where to write url path
+ * @pre `url != NULL`
+ *
+ * @param[in]   url         URL to split. Must not be NULL.
+ * @param[out]  hostport    where to write host:port. Can be NULL.
+ * @param[out]  urlpath     where to write url path. Can be NULL.
  *
  * @returns     0 on success
  * @returns     <0 otherwise
diff --git a/sys/net/sock/sock_util.c b/sys/net/sock/sock_util.c
index 6f265716f9eb..4045bc055b35 100644
--- a/sys/net/sock/sock_util.c
+++ b/sys/net/sock/sock_util.c
@@ -24,6 +24,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <assert.h>
 
 #include "net/sock/udp.h"
 #include "net/sock/util.h"
@@ -116,6 +117,7 @@ static char* _find_pathstart(const char *url)
 
 int sock_urlsplit(const char *url, char *hostport, char *urlpath)
 {
+    assert(url);
     char *hoststart = _find_hoststart(url);
     if (!hoststart) {
         return -EINVAL;
@@ -123,23 +125,25 @@ int sock_urlsplit(const char *url, char *hostport, char *urlpath)
 
     char *pathstart = _find_pathstart(hoststart);
 
-    size_t hostlen = pathstart - hoststart;
-    /* hostlen must be smaller SOCK_HOSTPORT_MAXLEN to have space for the null
-     * terminator */
-    if (hostlen > SOCK_HOSTPORT_MAXLEN - 1) {
-        return -EOVERFLOW;
+    if (hostport) {
+        size_t hostlen = pathstart - hoststart;
+        /* hostlen must be smaller SOCK_HOSTPORT_MAXLEN to have space for the null
+        * terminator */
+        if (hostlen > SOCK_HOSTPORT_MAXLEN - 1) {
+            return -EOVERFLOW;
+        }
+        memcpy(hostport, hoststart, hostlen);
+        hostport[hostlen] = '\0';
     }
-    memcpy(hostport, hoststart, hostlen);
-    *(hostport + hostlen) = '\0';
 
-    size_t pathlen = strlen(pathstart);
-    if (pathlen) {
+    if (urlpath) {
+        size_t pathlen = strlen(pathstart);
         if (pathlen > SOCK_URLPATH_MAXLEN - 1) {
             return -EOVERFLOW;
         }
         memcpy(urlpath, pathstart, pathlen);
+        urlpath[pathlen] = '\0';
     }
-    *(urlpath + pathlen) = '\0';
     return 0;
 }
 
diff --git a/tests/unittests/tests-sock_util/tests-sock_util.c b/tests/unittests/tests-sock_util/tests-sock_util.c
index ea46e538cdd4..d0677046148a 100644
--- a/tests/unittests/tests-sock_util/tests-sock_util.c
+++ b/tests/unittests/tests-sock_util/tests-sock_util.c
@@ -152,6 +152,18 @@ static void test_sock_util_urlsplit__urlpath_too_long(void)
             sock_urlsplit(TEST_URL_LONG_URLPATH, addr, urlpath));
 }
 
+static void test_sock_util_urlsplit__null_addr_buffer(void)
+{
+    TEST_ASSERT_EQUAL_INT(0, sock_urlsplit(TEST_URL, addr, NULL));
+    TEST_ASSERT_EQUAL_STRING(TEST_URL_HOSTPART, (char*)addr);
+}
+
+static void test_sock_util_urlsplit__null_path_buffer(void)
+{
+    TEST_ASSERT_EQUAL_INT(0, sock_urlsplit(TEST_URL, NULL, urlpath));
+    TEST_ASSERT_EQUAL_STRING(TEST_URL_LOCALPART, (char*)urlpath);
+}
+
 static void test_sock_util_str2ep__ipv6_noport(void)
 {
     sock_udp_ep_t ep;
@@ -210,6 +222,8 @@ Test *tests_sock_util_all(void)
         new_TestFixture(test_sock_util_urlsplit__no_schema),
         new_TestFixture(test_sock_util_urlsplit__hostport_too_long),
         new_TestFixture(test_sock_util_urlsplit__urlpath_too_long),
+        new_TestFixture(test_sock_util_urlsplit__null_addr_buffer),
+        new_TestFixture(test_sock_util_urlsplit__null_path_buffer),
         new_TestFixture(test_sock_util_str2ep__ipv6_noport),
         new_TestFixture(test_sock_util_str2ep__ipv4_noport),
         new_TestFixture(test_sock_util_str2ep__ipv4_port),