1 files changed, 3 insertions, 2 deletions

diff --git a/subprojects/language/src/main/java/tools/refinery/language/resource/ReferenceCounter.java b/subprojects/language/src/main/java/tools/refinery/language/resource/ReferenceCounter.java
index 7525dfc6..ca20325e 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/resource/ReferenceCounter.java
+++ b/subprojects/language/src/main/java/tools/refinery/language/resource/ReferenceCounter.java
@@ -5,6 +5,7 @@ import java.util.Map;
 
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.xtext.util.IResourceScopeCache;
+import org.eclipse.xtext.util.Tuples;
 
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
@@ -14,7 +15,7 @@ import tools.refinery.language.model.problem.Problem;
 @Singleton
 public class ReferenceCounter {
         @Inject
-        private IResourceScopeCache cache;
+        private IResourceScopeCache cache = IResourceScopeCache.NullImpl.INSTANCE;
 
         public int countReferences(Problem problem, EObject eObject) {
                 var count = getReferenceCounts(problem).get(eObject);
@@ -29,7 +30,7 @@ public class ReferenceCounter {
                 if (resource == null) {
                         return doGetReferenceCounts(problem);
                 }
-                return cache.get(problem, resource, () -> doGetReferenceCounts(problem));
+                return cache.get(Tuples.create(problem, "referenceCounts"), resource, () -> doGetReferenceCounts(problem));
         }
 
         protected Map<EObject, Integer> doGetReferenceCounts(Problem problem) {