diff --git a/clang/include/clang/Sema/SemaConcept.h b/clang/include/clang/Sema/SemaConcept.h
index 51ca1e16331f5..bdd997b18cb08 100644
--- a/clang/include/clang/Sema/SemaConcept.h
+++ b/clang/include/clang/Sema/SemaConcept.h
@@ -257,6 +257,7 @@ struct NormalizedConstraint {
     case ConstraintKind::FoldExpanded:
       return FoldExpanded.Pattern->getBeginLoc();
     }
+    llvm_unreachable("Unknown ConstraintKind enum");
   }
 
   SourceLocation getEndLoc() const {
@@ -270,6 +271,7 @@ struct NormalizedConstraint {
     case ConstraintKind::FoldExpanded:
       return FoldExpanded.Pattern->getEndLoc();
     }
+    llvm_unreachable("Unknown ConstraintKind enum");
   }
 
   SourceRange getSourceRange() const { return {getBeginLoc(), getEndLoc()}; }