diff --git a/plugins/org.eclipse.gmt.tcs.metadata/src/org/eclipse/gmt/tcs/metadata/adhoc/WorkspaceLanguage.java b/plugins/org.eclipse.gmt.tcs.metadata/src/org/eclipse/gmt/tcs/metadata/adhoc/WorkspaceLanguage.java
index 6647afb..c3a66e3 100644
--- a/plugins/org.eclipse.gmt.tcs.metadata/src/org/eclipse/gmt/tcs/metadata/adhoc/WorkspaceLanguage.java
+++ b/plugins/org.eclipse.gmt.tcs.metadata/src/org/eclipse/gmt/tcs/metadata/adhoc/WorkspaceLanguage.java
@@ -173,11 +173,18 @@
 		ecoreFile = project.getFile("Metamodel/" + name + ".ecore");
 		metamodelCache = new ModelCache() {
 			private long timestamp;
+			private String metamodelOverrideURI = properties.getProperty("override.metamodel.uri");
 
 			protected Object loadModel(ModelFactory factory) {
 				try {
-					Object ret = factory.loadMetamodel(name, ecoreFile.getContents());
-					this.timestamp = ecoreFile.getModificationStamp();
+					Object location;
+					if(metamodelOverrideURI != null) {
+						location = URI.createURI(metamodelOverrideURI);
+					} else {
+						location = ecoreFile.getContents();
+						this.timestamp = ecoreFile.getModificationStamp();
+					}
+					Object ret = factory.loadMetamodel(name, location);
 					return ret;
 				} catch (CoreException e) {
 					throw new RuntimeException(e);
@@ -185,10 +192,16 @@
 			}			
 
 			protected boolean shouldReload() {
-				return ecoreFile.getModificationStamp() != timestamp;
+				String newMetamodelOverrideURI = getProperty("override.metamodel.uri");
+				if(metamodelOverrideURI != newMetamodelOverrideURI) {
+					metamodelOverrideURI = newMetamodelOverrideURI;
+					return true;
+				} else {
+					return ecoreFile.getModificationStamp() != timestamp;
+				}
 			}
 		};
-		
+
 		antlrFile = project.getFile("Syntax/" + name + "_ANTLR3.g");
 		jarFile = project.getFile("Syntax/" + name + "-parser.jar");