diff --git a/org.omg.kerml.xpect.tests/src/org/omg/kerml/xpect/tests/parsing/ParsingTests_Metadata.kerml.xt b/org.omg.kerml.xpect.tests/src/org/omg/kerml/xpect/tests/parsing/ParsingTests_Metadata.kerml.xt
index 81e882f04e..83f8a6783e 100644
--- a/org.omg.kerml.xpect.tests/src/org/omg/kerml/xpect/tests/parsing/ParsingTests_Metadata.kerml.xt
+++ b/org.omg.kerml.xpect.tests/src/org/omg/kerml/xpect/tests/parsing/ParsingTests_Metadata.kerml.xt
@@ -74,4 +74,8 @@ package Metadata {
     #M struct T {
         feature :>> cc;
     }
+    
+    metaclass M1 {
+    	metadata M1;
+    }
 }
diff --git a/org.omg.sysml.logic.bundle/lib/org.omg.sysml.logic-0.63.0-SNAPSHOT.jar b/org.omg.sysml.logic.bundle/lib/org.omg.sysml.logic-0.63.0-SNAPSHOT.jar
index 9f62f5b33a..202bc9af99 100644
Binary files a/org.omg.sysml.logic.bundle/lib/org.omg.sysml.logic-0.63.0-SNAPSHOT.jar and b/org.omg.sysml.logic.bundle/lib/org.omg.sysml.logic-0.63.0-SNAPSHOT.jar differ
diff --git a/org.omg.sysml.logic/src/main/java/org/omg/sysml/adapter/TypeAdapter.java b/org.omg.sysml.logic/src/main/java/org/omg/sysml/adapter/TypeAdapter.java
index 45a5e4bcca..8501a829f7 100644
--- a/org.omg.sysml.logic/src/main/java/org/omg/sysml/adapter/TypeAdapter.java
+++ b/org.omg.sysml.logic/src/main/java/org/omg/sysml/adapter/TypeAdapter.java
@@ -482,11 +482,13 @@ public Type getLibraryType(String... defaultNames) {
 	protected List<Type> getBaseTypes() {
 		List<Type> baseTypes = new ArrayList<>();
 		if (isGetBaseTypes) {
+			Set<Feature> visited = new HashSet<>();
 			Type target = getTarget();
 			for (MetadataFeature metadataFeature : ElementUtil.getAllMetadataFeaturesOf(target)) {
 				// Resolve metaclass proxy before getting base type, to avoid problems
-				// with name resolution when applying semantic metadata.
-				metadataFeature.getMetaclass();
+				// with name resolution when applying semantic metadata. (ST6RI-923)
+				// Call getTypesOf rather than getMetaclass to avoid possible stack overflow. (ST6RI-976)
+				FeatureUtil.getTypesOf(metadataFeature, new ArrayList<>(), visited);
 				isGetBaseTypes = false;
 				TypeUtil.getFeatureOf(metadataFeature).stream().
 						filter(f->TypeUtil.specializes(f, getBaseTypeFeature(metadataFeature))).
diff --git a/org.omg.sysml.model.bundle/lib/org.omg.sysml.model-0.63.0-SNAPSHOT.jar b/org.omg.sysml.model.bundle/lib/org.omg.sysml.model-0.63.0-SNAPSHOT.jar
index 14d2eb57e4..e16b22f8e1 100644
Binary files a/org.omg.sysml.model.bundle/lib/org.omg.sysml.model-0.63.0-SNAPSHOT.jar and b/org.omg.sysml.model.bundle/lib/org.omg.sysml.model-0.63.0-SNAPSHOT.jar differ
diff --git a/org.omg.sysml.xpect.tests/src/org/omg/sysml/xpect/tests/simpletests/MetadataTest.sysml.xt b/org.omg.sysml.xpect.tests/src/org/omg/sysml/xpect/tests/simpletests/MetadataTest.sysml.xt
index 1cf9aac311..e0b9f21e93 100644
--- a/org.omg.sysml.xpect.tests/src/org/omg/sysml/xpect/tests/simpletests/MetadataTest.sysml.xt
+++ b/org.omg.sysml.xpect.tests/src/org/omg/sysml/xpect/tests/simpletests/MetadataTest.sysml.xt
@@ -72,6 +72,10 @@ package MetadataTest {
 	    #Security #Classified metadata Classified {
 	        classificationLevel = ClassificationLevel::secret;
 	    }
-	}	
+	}
+	
+	metadata def M {
+		metadata M;	
+	}
 	
 }
\ No newline at end of file