diff --git a/src/wrtembed/KReportDesigner.cpp b/src/wrtembed/KReportDesigner.cpp
--- a/src/wrtembed/KReportDesigner.cpp
+++ b/src/wrtembed/KReportDesigner.cpp
@@ -388,6 +388,9 @@
     content.appendChild(propertyToElement(&doc, d->title));
 
 #ifdef KREPORT_SCRIPTING
+    if (d->originalInterpreter.isEmpty()) {
+        d->originalInterpreter = QLatin1String("javascript");
+    }
     saveInterpreter = d->originalInterpreter;
 
     if (!d->script->value().toString().isEmpty()) {