diff --git a/llvm/include/llvm/Transforms/IPO/FunctionImport.h b/llvm/include/llvm/Transforms/IPO/FunctionImport.h
index 6df597c300c18..5dad572532c8a 100644
--- a/llvm/include/llvm/Transforms/IPO/FunctionImport.h
+++ b/llvm/include/llvm/Transforms/IPO/FunctionImport.h
@@ -42,7 +42,7 @@ class FunctionImporter {
 
   /// The different reasons selectCallee will chose not to import a
   /// candidate.
-  enum ImportFailureReason {
+  enum class ImportFailureReason {
     None,
     // We can encounter a global variable instead of a function in rare
     // situations with SamplePGO. See comments where this failure type is