diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/CPreprocessor.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/CPreprocessor.java
index 4d20d06394f..3b3eeb9d3c4 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/CPreprocessor.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/CPreprocessor.java
@@ -1822,7 +1822,7 @@ public class CPreprocessor implements ILexerLog, IScanner, IAdaptable {
 		}
         PreprocessorMacro macro= fMacroDictionary.get(name);
         if (macro == null) {
-        	if ((options & IGNORE_UNDEFINED_SIGNIFICANT_MACROS) == 0) 
+        	if (reportSignificant && (options & IGNORE_UNDEFINED_SIGNIFICANT_MACROS) == 0) 
         		fCurrentContext.significantMacroUndefined(name);
         	return false;
         }