diff --git a/lib/Conversion/SCFToCalyx/SCFToCalyx.cpp b/lib/Conversion/SCFToCalyx/SCFToCalyx.cpp
index a19029255843..6ef0da7e0a68 100644
--- a/lib/Conversion/SCFToCalyx/SCFToCalyx.cpp
+++ b/lib/Conversion/SCFToCalyx/SCFToCalyx.cpp
@@ -330,7 +330,7 @@ class BuildOpGroups : public calyx::FuncOpPartialLoweringPattern {
         std::ofstream outFile(outFileName);
 
         if (!outFile.is_open()) {
-          llvm::errs() << "Unable to open file: " << outFileName
+          llvm::errs() << "Unable to open file: " << outFileName.string()
                        << " for writing\n";
           return failure();
         }