1 files changed, 1 insertions, 0 deletions
diff --git a/src/shared/cplusplus/CPlusPlusForwardDeclarations.h b/src/shared/cplusplus/CPlusPlusForwardDeclarations.h
index 31b01bfd81..2909c0775a 100644
--- a/src/shared/cplusplus/CPlusPlusForwardDeclarations.h
+++ b/src/shared/cplusplus/CPlusPlusForwardDeclarations.h
@@ -108,6 +108,7 @@ class QualifiedNameId;
 class FullySpecifiedType;
 class TypeVisitor;
 class Type;
+class UndefinedType;
 class VoidType;
 class IntegerType;
 class FloatType;