diff --git a/include/toml++/impl/parser.inl b/include/toml++/impl/parser.inl
index 7aa9afb3..f780cd8a 100644
--- a/include/toml++/impl/parser.inl
+++ b/include/toml++/impl/parser.inl
@@ -3763,7 +3763,7 @@ TOML_ANON_NAMESPACE_START
 		TOML_OVERALIGNED char file_buffer[sizeof(void*) * 1024u];
 		file.rdbuf()->pubsetbuf(file_buffer, sizeof(file_buffer));
 #if TOML_WINDOWS
-		file.open(impl::widen(file_path_str), std::ifstream::in | std::ifstream::binary | std::ifstream::ate);
+		file.open(impl::widen(file_path_str).c_str(), std::ifstream::in | std::ifstream::binary | std::ifstream::ate);
 #else
 		file.open(file_path_str, std::ifstream::in | std::ifstream::binary | std::ifstream::ate);
 #endif
diff --git a/toml.hpp b/toml.hpp
index 5e4c7f8c..7f48c7da 100644
--- a/toml.hpp
+++ b/toml.hpp
@@ -15772,7 +15772,7 @@ TOML_ANON_NAMESPACE_START
 		TOML_OVERALIGNED char file_buffer[sizeof(void*) * 1024u];
 		file.rdbuf()->pubsetbuf(file_buffer, sizeof(file_buffer));
 #if TOML_WINDOWS
-		file.open(impl::widen(file_path_str), std::ifstream::in | std::ifstream::binary | std::ifstream::ate);
+		file.open(impl::widen(file_path_str).c_str(), std::ifstream::in | std::ifstream::binary | std::ifstream::ate);
 #else
 		file.open(file_path_str, std::ifstream::in | std::ifstream::binary | std::ifstream::ate);
 #endif