diff --git a/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/batch/ClasspathDirectory.java b/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/batch/ClasspathDirectory.java
index 53ccd91bfa4..c2f332dcc41 100644
--- a/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/batch/ClasspathDirectory.java
+++ b/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/batch/ClasspathDirectory.java
@@ -230,7 +230,7 @@ private Map<String, String> getSecondaryTypes(String qualifiedPackageName) {
 		Parser parser = new Parser(problemReporter, false);
 		parser.reportSyntaxErrorIsRequired = false;
 
-		CompilationUnitDeclaration unit = parser.parse(cu, compilationResult);
+		CompilationUnitDeclaration unit = parser.dietParse(cu, compilationResult);
 		org.eclipse.jdt.internal.compiler.ast.TypeDeclaration[] types = unit != null ? unit.types : null;
 		if (types == null) continue;
 		for (TypeDeclaration type : types) {