diff --git a/shared/systemd/nm-sd-utils-shared.c b/shared/systemd/nm-sd-utils-shared.c
index 85fd6a353e..b4e017c94b 100644
--- a/shared/systemd/nm-sd-utils-shared.c
+++ b/shared/systemd/nm-sd-utils-shared.c
@@ -13,6 +13,7 @@
 #include "hexdecoct.h"
 #include "hostname-util.h"
 #include "path-util.h"
+#include "web-util.h"
 
 /*****************************************************************************/
 
@@ -94,3 +95,40 @@ gboolean nm_sd_hostname_is_valid (const char *s, bool allow_trailing_dot)
 {
 	return hostname_is_valid (s, allow_trailing_dot);
 }
+
+/*****************************************************************************/
+
+static gboolean
+_http_url_is_valid (const char *url)
+{
+	if (   !url
+	    || !url[0])
+		return FALSE;
+
+	if (NM_STR_HAS_PREFIX (url, "http://"))
+		url += NM_STRLEN ("http://");
+	else if (NM_STR_HAS_PREFIX (url, "https://"))
+		url += NM_STRLEN ("https://");
+	else
+		return FALSE;
+
+	if (!url[0])
+		return FALSE;
+
+	return !NM_STRCHAR_ANY (url, ch, (guchar) ch >= 128u);
+}
+
+gboolean
+nm_sd_http_url_is_valid (const char *url)
+{
+	gboolean v;
+
+	/* http_url_is_valid() is part of our API, as we use it to validate connection
+	 * properties. That means, it's behavior must remain stable (or only change
+	 * with care).
+	 *
+	 * Thus, reimplement it, and make sure that our implementation agrees. */
+	v = _http_url_is_valid (url);
+	nm_assert (v == http_url_is_valid (url));
+	return v;
+}
diff --git a/shared/systemd/nm-sd-utils-shared.h b/shared/systemd/nm-sd-utils-shared.h
index 3495a31d19..382db278d1 100644
--- a/shared/systemd/nm-sd-utils-shared.h
+++ b/shared/systemd/nm-sd-utils-shared.h
@@ -34,4 +34,8 @@ int nm_sd_dns_name_to_wire_format (const char *domain,
 int nm_sd_dns_name_is_valid (const char *s);
 gboolean nm_sd_hostname_is_valid(const char *s, bool allow_trailing_dot);
 
+/*****************************************************************************/
+
+gboolean nm_sd_http_url_is_valid (const char *url);
+
 #endif /* __NM_SD_UTILS_SHARED_H__ */
diff --git a/shared/systemd/src/shared/web-util.c b/shared/systemd/src/shared/web-util.c
index f5a5362bd5..4cff5e271d 100644
--- a/shared/systemd/src/shared/web-util.c
+++ b/shared/systemd/src/shared/web-util.c
@@ -24,21 +24,25 @@ bool http_etag_is_valid(const char *etag) {
 }
 #endif /* NM_IGNORED */
 
-bool http_url_is_valid(const char *url) {
-        const char *p;
-
-        if (isempty(url))
-                return false;
-
-        p = STARTSWITH_SET(url, "http://", "https://");
-        if (!p)
-                return false;
-
-        if (isempty(p))
-                return false;
-
-        return ascii_is_valid(p);
-}
+/* NM: we use http_url_is_valid() for our own code, and it must not
+ * change behavior. If a re-import results in a merge-conflict, you must
+ * ensure that it does not change behavior, and possibly do something
+ * about that. */
+/**/   bool http_url_is_valid(const char *url) {
+/**/           const char *p;
+/**/
+/**/           if (isempty(url))
+/**/                   return false;
+/**/
+/**/           p = STARTSWITH_SET(url, "http://", "https://");
+/**/           if (!p)
+/**/                   return false;
+/**/
+/**/           if (isempty(p))
+/**/                   return false;
+/**/
+/**/           return ascii_is_valid(p);
+/**/   }
 
 #if 0 /* NM_IGNORED */
 bool documentation_url_is_valid(const char *url) {