diff --git a/lib/CompilerDriver/CompilationGraph.cpp b/lib/CompilerDriver/CompilationGraph.cpp
index 0e8f5d5..87a2c48 100644
--- a/lib/CompilerDriver/CompilationGraph.cpp
+++ b/lib/CompilerDriver/CompilationGraph.cpp
@@ -32,7 +32,7 @@
 namespace llvmc {
 
   const std::string* LanguageMap::GetLanguage(const sys::Path& File) const {
-    StringRef suf = sys::path::extension(File.str());
+    StringRef suf = File.getSuffix();
     LanguageMap::const_iterator Lang =
       this->find(suf.empty() ? "*empty*" : suf);
     if (Lang == this->end()) {