diff --git a/libnm-core/nm-core-internal.h b/libnm-core/nm-core-internal.h
index 471353e741..2a1c69d94b 100644
--- a/libnm-core/nm-core-internal.h
+++ b/libnm-core/nm-core-internal.h
@@ -329,7 +329,6 @@ gboolean _nm_utils_inet6_is_token (const struct in6_addr *in6addr);
 
 /***********************************************************/
 
-gboolean    _nm_utils_check_valid_json  (const char *json, GError **error);
 gboolean    _nm_utils_team_config_equal (const char *conf1, const char *conf2, gboolean port);
 
 #endif
diff --git a/libnm-core/nm-keyfile-reader.c b/libnm-core/nm-keyfile-reader.c
index 16f0c225b9..f25fa0e1a4 100644
--- a/libnm-core/nm-keyfile-reader.c
+++ b/libnm-core/nm-keyfile-reader.c
@@ -1175,7 +1175,7 @@ team_config_parser (KeyfileReaderInfo *info, NMSetting *setting, const char *key
 	gs_free_error GError *error = NULL;
 
 	conf = nm_keyfile_plugin_kf_get_string (info->keyfile, setting_name, key, NULL);
-	if (conf && conf[0] && !_nm_utils_check_valid_json (conf, &error)) {
+	if (conf && conf[0] && !nm_utils_is_json_object (conf, &error)) {
 		handle_warn (info, key, NM_KEYFILE_WARN_SEVERITY_WARN,
 		             _("ignoring invalid team configuration: %s"),
 		             error->message);
diff --git a/libnm-core/nm-setting-team-port.c b/libnm-core/nm-setting-team-port.c
index e3ddbdad7c..649d958273 100644
--- a/libnm-core/nm-setting-team-port.c
+++ b/libnm-core/nm-setting-team-port.c
@@ -117,7 +117,7 @@ verify (NMSetting *setting, NMConnection *connection, GError **error)
 	}
 
 	if (priv->config) {
-		if (!_nm_utils_check_valid_json (priv->config, error)) {
+		if (!nm_utils_is_json_object (priv->config, error)) {
 			g_prefix_error (error,
 			                "%s.%s: ",
 			                NM_SETTING_TEAM_PORT_SETTING_NAME,
diff --git a/libnm-core/nm-setting-team.c b/libnm-core/nm-setting-team.c
index 5bf11ed921..c49ebff2b2 100644
--- a/libnm-core/nm-setting-team.c
+++ b/libnm-core/nm-setting-team.c
@@ -89,7 +89,7 @@ verify (NMSetting *setting, NMConnection *connection, GError **error)
 		return FALSE;
 
 	if (priv->config) {
-		if (!_nm_utils_check_valid_json (priv->config, error)) {
+		if (!nm_utils_is_json_object (priv->config, error)) {
 			g_prefix_error (error,
 			                "%s.%s: ",
 			                NM_SETTING_TEAM_SETTING_NAME,
diff --git a/libnm-core/nm-utils.c b/libnm-core/nm-utils.c
index 818b0c43ec..cd54ba6b5f 100644
--- a/libnm-core/nm-utils.c
+++ b/libnm-core/nm-utils.c
@@ -4407,8 +4407,20 @@ const char **nm_utils_enum_get_values (GType type, gint from, gint to)
 }
 
 #if WITH_JANSSON
+/**
+ * nm_utils_is_json_object:
+ * @str: the JSON string to test
+ * @error: optional error reason
+ *
+ * Returns: whether the passed string is valid JSON.
+ *   If libnm is not compiled with libjansson support, this check will
+ *   also return %TRUE for possibly invalid inputs. If that is a problem
+ *   for you, you must validate the JSON yourself.
+ *
+ * Since: 1.6
+ */
 gboolean
-_nm_utils_check_valid_json (const char *str, GError **error)
+nm_utils_is_json_object (const char *str, GError **error)
 {
 	json_t *json;
 	json_error_t jerror;
@@ -4419,7 +4431,7 @@ _nm_utils_check_valid_json (const char *str, GError **error)
 		g_set_error_literal (error,
 		                     NM_CONNECTION_ERROR,
 		                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
-		                     "value is NULL or empty");
+		                     str ? _("value is NULL") : _("value is empty"));
 		return FALSE;
 	}
 
@@ -4428,9 +4440,19 @@ _nm_utils_check_valid_json (const char *str, GError **error)
 		g_set_error (error,
 		             NM_CONNECTION_ERROR,
 		             NM_CONNECTION_ERROR_INVALID_PROPERTY,
-		             "%s at position %d",
-		             jerror.text,
-		             jerror.position);
+		             _("invalid JSON at position %d (%s)"),
+		             jerror.position,
+		             jerror.text);
+		return FALSE;
+	}
+
+	/* valid JSON (depending on the definition) can also be a literal.
+	 * Here we only allow objects. */
+	if (!json_is_object (json)) {
+		g_set_error_literal (error,
+		                     NM_CONNECTION_ERROR,
+		                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
+		                     _("is not a JSON object"));
 		return FALSE;
 	}
 
@@ -4522,17 +4544,48 @@ out:
 #else /* WITH_JANSSON */
 
 gboolean
-_nm_utils_check_valid_json (const char *str, GError **error)
+nm_utils_is_json_object (const char *str, GError **error)
 {
+	g_return_val_if_fail (!error || !*error, FALSE);
+
+	if (str) {
+		/* libjansson also requires only utf-8 encoding. */
+		if (!g_utf8_validate (str, -1, NULL)) {
+			g_set_error_literal (error,
+			                     NM_CONNECTION_ERROR,
+			                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
+			                     _("not valid utf-8"));
+			return FALSE;
+		}
+		while (g_ascii_isspace (str[0]))
+			str++;
+	}
+
 	if (!str || !str[0]) {
 		g_set_error_literal (error,
 		                     NM_CONNECTION_ERROR,
 		                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
-		                     "value is NULL or empty");
+		                     str ? _("value is NULL") : _("value is empty"));
 		return FALSE;
 	}
 
-	return TRUE;
+	/* do some very basic validation to see if this might be a JSON object. */
+	if (str[0] == '{') {
+		g_size l;
+
+		l = strlen (str) - 1;
+		while (l > 0 && g_ascii_isspace (str[l]))
+			l--;
+
+		if (str[l] == '}')
+			return TRUE;
+	}
+
+	g_set_error_literal (error,
+	                     NM_CONNECTION_ERROR,
+	                     NM_CONNECTION_ERROR_INVALID_PROPERTY,
+	                     _("is not a JSON object"));
+	return FALSE;
 }
 
 gboolean
diff --git a/libnm-core/nm-utils.h b/libnm-core/nm-utils.h
index 407c14e2c4..4fabfdb7b7 100644
--- a/libnm-core/nm-utils.h
+++ b/libnm-core/nm-utils.h
@@ -90,6 +90,9 @@ gboolean nm_utils_ap_mode_security_valid (NMUtilsSecurityType type,
 gboolean nm_utils_wep_key_valid (const char *key, NMWepKeyType wep_type);
 gboolean nm_utils_wpa_psk_valid (const char *psk);
 
+NM_AVAILABLE_IN_1_6
+gboolean nm_utils_is_json_object (const char *json, GError **error);
+
 GVariant  *nm_utils_ip4_dns_to_variant (char **dns);
 char     **nm_utils_ip4_dns_from_variant (GVariant *value);
 GVariant  *nm_utils_ip4_addresses_to_variant (GPtrArray *addresses,
diff --git a/libnm-core/tests/test-general.c b/libnm-core/tests/test-general.c
index e8a9404bf3..c75abbf999 100644
--- a/libnm-core/tests/test-general.c
+++ b/libnm-core/tests/test-general.c
@@ -4685,7 +4685,7 @@ _json_config_check_valid (const char *conf, gboolean expected)
 	gs_free_error GError *error = NULL;
 	gboolean res;
 
-	res = _nm_utils_check_valid_json (conf, &error);
+	res = nm_utils_is_json_object (conf, &error);
 	g_assert_cmpint (res, ==, expected);
 	g_assert (res || error);
 }
diff --git a/libnm/libnm.ver b/libnm/libnm.ver
index 6c149f6587..bc47e8625d 100644
--- a/libnm/libnm.ver
+++ b/libnm/libnm.ver
@@ -1086,4 +1086,5 @@ global:
 
 libnm_1_6_0 {
 	nm_capability_get_type;
+	nm_utils_is_json_object;
 } libnm_1_4_0;
diff --git a/src/settings/plugins/ifcfg-rh/reader.c b/src/settings/plugins/ifcfg-rh/reader.c
index 5a351cfa06..80c6ca1553 100644
--- a/src/settings/plugins/ifcfg-rh/reader.c
+++ b/src/settings/plugins/ifcfg-rh/reader.c
@@ -4258,7 +4258,7 @@ read_team_config (shvarFile *ifcfg, const char *key, GError **error)
 	}
 	svUnescape (value);
 
-	if (value && value[0] && !_nm_utils_check_valid_json (value, &local_error)) {
+	if (value && value[0] && !nm_utils_is_json_object (value, &local_error)) {
 		PARSE_WARNING ("ignoring invalid team configuration: %s", local_error->message);
 		g_clear_pointer (&value, g_free);
 	}