diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/CCompletionContributorDescriptor.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/CCompletionContributorDescriptor.java
index 94070ef38f4..cc2cff67981 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/CCompletionContributorDescriptor.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/CCompletionContributorDescriptor.java
@@ -78,7 +78,8 @@ public class CCompletionContributorDescriptor {
 				CUIPlugin.getDefault().log(e);
 			}
 		}
-		return false;
+		// For backward compat. we have to return true in no enablement was specified.
+		return true;
 	}
 
 	public ICCompletionContributor getCCompletionContributor(ITranslationUnit cunit) throws CoreException {
@@ -123,7 +124,8 @@ public class CCompletionContributorDescriptor {
 				CUIPlugin.getDefault().log(e);
 			}
 		}
-		return false;
+		// For backward compat. we have to return true in no enablement was specified.
+		return true;
 	}
 
 	public ICCompletionContributor getCCompletionContributor(IProject project) throws CoreException {