diff --git a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistant.java b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistant.java
index 3c4a834..21e307e 100644
--- a/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistant.java
+++ b/org.eclipse.jface.text/src/org/eclipse/jface/text/contentassist/ContentAssistant.java
@@ -349,6 +349,8 @@
 		}
 
 		protected void showAssist(final int showStyle) {
+			if (fContentAssistSubjectControlAdapter == null)
+				return;
 			final Control control= fContentAssistSubjectControlAdapter.getControl();
 			if (control == null)
 				return;