diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CSourceHover.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CSourceHover.java
index f11d5fe1bdf..97a5563c0eb 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CSourceHover.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CSourceHover.java
@@ -611,7 +611,7 @@ public class CSourceHover extends AbstractCEditorTextHover {
 
 				String[] sourceLines= Strings.convertIntoLines(source);
 				String firstLine= sourceLines[0];
-				if (!Character.isWhitespace(firstLine.charAt(0)))
+				if (firstLine.length() > 0 && !Character.isWhitespace(firstLine.charAt(0)))
 					sourceLines[0]= ""; //$NON-NLS-1$
 				Strings.trimIndentation(sourceLines, getTabWidth(), getTabWidth());