diff --git a/shared/systemd/nm-sd-utils-shared.c b/shared/systemd/nm-sd-utils-shared.c
index 7206fa52b9..805c8403c5 100644
--- a/shared/systemd/nm-sd-utils-shared.c
+++ b/shared/systemd/nm-sd-utils-shared.c
@@ -22,9 +22,10 @@
 
 #include "nm-sd-adapt-shared.h"
 
-#include "path-util.h"
-#include "hexdecoct.h"
 #include "dns-domain.h"
+#include "hexdecoct.h"
+#include "hostname-util.h"
+#include "path-util.h"
 
 /*****************************************************************************/
 
@@ -52,7 +53,7 @@ nm_sd_utils_path_startswith (const char *path, const char *prefix)
 
 /*****************************************************************************/
 
-gboolean
+int
 nm_sd_utils_unbase64char (char ch, gboolean accept_padding_equal)
 {
 	if (   ch == '='
@@ -96,3 +97,13 @@ int nm_sd_dns_name_to_wire_format (const char *domain,
 {
 	return dns_name_to_wire_format (domain, buffer, len, canonical);
 }
+
+int nm_sd_dns_name_is_valid (const char *s)
+{
+	return dns_name_is_valid (s);
+}
+
+gboolean nm_sd_hostname_is_valid (const char *s, bool allow_trailing_dot)
+{
+	return hostname_is_valid (s, allow_trailing_dot);
+}
diff --git a/shared/systemd/nm-sd-utils-shared.h b/shared/systemd/nm-sd-utils-shared.h
index 48a8cf37ac..5465a01aca 100644
--- a/shared/systemd/nm-sd-utils-shared.h
+++ b/shared/systemd/nm-sd-utils-shared.h
@@ -44,4 +44,7 @@ int nm_sd_dns_name_to_wire_format (const char *domain,
                                    size_t len,
                                    gboolean canonical);
 
+int nm_sd_dns_name_is_valid (const char *s);
+gboolean nm_sd_hostname_is_valid(const char *s, bool allow_trailing_dot);
+
 #endif /* __NM_SD_UTILS_SHARED_H__ */
diff --git a/src/dhcp/nm-dhcp-manager.c b/src/dhcp/nm-dhcp-manager.c
index 304a7b9961..943620c9a2 100644
--- a/src/dhcp/nm-dhcp-manager.c
+++ b/src/dhcp/nm-dhcp-manager.c
@@ -32,6 +32,7 @@
 #include <stdio.h>
 
 #include "nm-glib-aux/nm-dedup-multi.h"
+#include "systemd/nm-sd-utils-shared.h"
 
 #include "nm-config.h"
 #include "NetworkManagerUtils.h"
@@ -251,6 +252,17 @@ client_start (NMDhcpManager *self,
 		g_return_val_if_reached (NULL) ;
 	}
 
+	if (hostname) {
+		if (   (hostname_use_fqdn && !nm_sd_dns_name_is_valid (hostname))
+		    || (!hostname_use_fqdn && !nm_sd_hostname_is_valid (hostname, FALSE))) {
+			nm_log_warn (LOGD_DHCP , "dhcp%c: %s '%s' is invalid, will be ignored",
+			             nm_utils_addr_family_to_char (addr_family),
+			             hostname_use_fqdn ? "FQDN" : "hostname",
+			             hostname);
+			hostname = NULL;
+		}
+	}
+
 	nm_assert (g_bytes_get_size (hwaddr) == g_bytes_get_size (bcast_hwaddr));
 
 	priv = NM_DHCP_MANAGER_GET_PRIVATE (self);