diff --git a/gen/todebug.cpp b/gen/todebug.cpp
index 65f29570..de5bdfa2 100644
--- a/gen/todebug.cpp
+++ b/gen/todebug.cpp
@@ -141,7 +141,7 @@ static LLGlobalVariable* dwarfCompileUnit(Module* m)
         llvm::sys::Path tmp = llvm::sys::Path::GetCurrentDirectory();
         tmp.appendComponent(srcpath);
         srcpath = tmp.toString();
-        if (*srcpath.rbegin() != '/' || *srcpath.rbegin() != '\\')
+        if (!srcpath.empty() && *srcpath.rbegin() != '/' && *srcpath.rbegin() != '\\')
             srcpath = srcpath + '/';
     }
     vals[4] = DtoConstStringPtr(srcpath.c_str(), "llvm.metadata");