diff --git a/ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/views/imagebrowser/repositories/AbstractRepository.java b/ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/views/imagebrowser/repositories/AbstractRepository.java
index 9b72173bb32..62ed8f8f17c 100644
--- a/ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/views/imagebrowser/repositories/AbstractRepository.java
+++ b/ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/views/imagebrowser/repositories/AbstractRepository.java
@@ -45,7 +45,7 @@
 
 public abstract class AbstractRepository extends Job {
 
-	private SequencedMap<String, ImageElement> mElementsCache = new LinkedHashMap<>();
+	private final SequencedMap<String, ImageElement> mElementsCache = new LinkedHashMap<>();
 
 	private final IImageTarget mTarget;