diff --git a/llvm/include/llvm/Analysis/OptimizationRemarkEmitter.h b/llvm/include/llvm/Analysis/OptimizationRemarkEmitter.h
index b89ea496cd8a..ab97d5b8504e 100644
--- a/llvm/include/llvm/Analysis/OptimizationRemarkEmitter.h
+++ b/llvm/include/llvm/Analysis/OptimizationRemarkEmitter.h
@@ -17,11 +17,11 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/IR/DiagnosticInfo.h"
-#include "llvm/IR/Function.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
 
 namespace llvm {
+class Function;
 class Value;
 
 /// The optimization diagnostic interface.