diff --git a/lib/Frontend/PrintPreprocessedOutput.cpp b/lib/Frontend/PrintPreprocessedOutput.cpp
index 432428b..6734d77 100644
--- a/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -140,6 +140,7 @@
   virtual void PragmaComment(SourceLocation Loc, const IdentifierInfo *Kind,
                              const std::string &Str);
   virtual void PragmaMessage(SourceLocation Loc, StringRef Str);
+  virtual void PragmaDebug(SourceLocation Loc, StringRef DebugType);
   virtual void PragmaDiagnosticPush(SourceLocation Loc,
                                     StringRef Namespace);
   virtual void PragmaDiagnosticPop(SourceLocation Loc,
@@ -419,6 +420,17 @@
   setEmittedDirectiveOnThisLine();
 }
 
+void PrintPPOutputPPCallbacks::PragmaDebug(SourceLocation Loc,
+                                           StringRef DebugType) {
+  startNewLineIfNeeded();
+  MoveToLine(Loc);
+
+  OS << "#pragma clang __debug ";
+  OS << DebugType;
+
+  setEmittedDirectiveOnThisLine();
+}
+
 void PrintPPOutputPPCallbacks::
 PragmaDiagnosticPush(SourceLocation Loc, StringRef Namespace) {
   startNewLineIfNeeded();