diff --git a/llvm/utils/TableGen/GICombinerEmitter.cpp b/llvm/utils/TableGen/GICombinerEmitter.cpp
index f30ae86c4fa0..ec3448c59008 100644
--- a/llvm/utils/TableGen/GICombinerEmitter.cpp
+++ b/llvm/utils/TableGen/GICombinerEmitter.cpp
@@ -332,7 +332,7 @@ bool CombineRule::parseDefs() {
             getDefOfSubClass(*Defs->getArg(I), "GIDefMatchData")) {
       declareMatchData(Defs->getArgNameStr(I),
                        MatchDataRec->getValueAsString("Type"),
-                       llvm::to_string(llvm::format("MatchData%d", ID)));
+                       llvm::to_string(llvm::format("MatchData%" PRIu64, ID)));
       continue;
     }