diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/components/FilteredCheckboxTree.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/components/FilteredCheckboxTree.java
index 29795bf..9daf96d 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/components/FilteredCheckboxTree.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/components/FilteredCheckboxTree.java
@@ -126,11 +126,12 @@
 	@Override
 	protected String getFilterString() {
 		String filterString = super.getFilterString();
-		if (!filterText.getText().equals(initialText)
-				&& filterString.indexOf("*") != 0 //$NON-NLS-1$
-				&& filterString.indexOf("?") != 0 //$NON-NLS-1$
-				&& filterString.indexOf(".") != 0) {//$NON-NLS-1$
-			filterString = "*" + filterString; //$NON-NLS-1$
+		if (filterString != null
+				&& !filterString.equals(initialText)
+				&& filterString.indexOf('*') != 0
+				&& filterString.indexOf('?') != 0
+				&& filterString.indexOf('.') != 0) {
+			filterString = '*' + filterString;
 		}
 		return filterString;
 	}