diff --git a/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/contentassist/CustomCompletionProposal.java b/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/contentassist/CustomCompletionProposal.java
index ba738a0..f39ba52 100644
--- a/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/contentassist/CustomCompletionProposal.java
+++ b/bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/contentassist/CustomCompletionProposal.java
@@ -310,7 +310,7 @@
 			return false;
 		boolean validated = startsWith(document, offset, fDisplayString);
 
-		if (fUpdateLengthOnValidate) {
+		if (fUpdateLengthOnValidate && event != null) {
 			fReplacementLength += event.fText.length() - event.fLength; //adjust the replacement length by the event's text replacement
 		}
 		return validated;