diff --git a/llvm/include/llvm/TableGen/Main.h b/llvm/include/llvm/TableGen/Main.h
--- a/llvm/include/llvm/TableGen/Main.h
+++ b/llvm/include/llvm/TableGen/Main.h
@@ -22,7 +22,7 @@
 /// Returns true on error, false otherwise.
 using TableGenMainFn = bool (raw_ostream &OS, RecordKeeper &Records);
 
-int TableGenMain(char *argv0, TableGenMainFn *MainFn);
+int TableGenMain(const char *argv0, TableGenMainFn *MainFn);
 
 } // end namespace llvm
 
diff --git a/llvm/lib/TableGen/Main.cpp b/llvm/lib/TableGen/Main.cpp
--- a/llvm/lib/TableGen/Main.cpp
+++ b/llvm/lib/TableGen/Main.cpp
@@ -80,7 +80,7 @@
   return 0;
 }
 
-int llvm::TableGenMain(char *argv0, TableGenMainFn *MainFn) {
+int llvm::TableGenMain(const char *argv0, TableGenMainFn *MainFn) {
   RecordKeeper Records;
 
   // Parse the input file.