diff --git a/src/conf/snapshot_conf.c b/src/conf/snapshot_conf.c
index aa2b5268b47ab8ff3d4f776565f08e5671398648..bff045583199ae8d847431eb1abaedee1c9d8b65 100644
--- a/src/conf/snapshot_conf.c
+++ b/src/conf/snapshot_conf.c
@@ -293,6 +293,12 @@ virDomainSnapshotDefParseString(const char *xmlStr,
                            memoryFile);
             goto cleanup;
         }
+        if (!memoryFile &&
+            def->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL) {
+            virReportError(VIR_ERR_XML_ERROR, "%s",
+                           _("external memory snapshots require a filename"));
+            goto cleanup;
+        }
     } else if (memoryFile) {
         def->memory = VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
     } else if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE) {