diff --git a/src/fs/Charset.cxx b/src/fs/Charset.cxx
index 71cd96908..d1e1a7079 100644
--- a/src/fs/Charset.cxx
+++ b/src/fs/Charset.cxx
@@ -92,13 +92,8 @@ FixSeparators(const PathTraitsUTF8::string_view _s)
 }
 
 PathTraitsUTF8::string
-PathToUTF8(PathTraitsFS::const_pointer path_fs)
+PathToUTF8(PathTraitsFS::string_view path_fs)
 {
-#if !CLANG_CHECK_VERSION(3,6)
-	/* disabled on clang due to -Wtautological-pointer-compare */
-	assert(path_fs != nullptr);
-#endif
-
 #ifdef _WIN32
 	const auto buffer = WideCharToMultiByte(CP_UTF8, path_fs);
 	return FixSeparators(buffer);
diff --git a/src/fs/Charset.hxx b/src/fs/Charset.hxx
index f387176f9..06c794e22 100644
--- a/src/fs/Charset.hxx
+++ b/src/fs/Charset.hxx
@@ -44,9 +44,8 @@ DeinitFSCharset() noexcept;
  *
  * Throws std::runtime_error on error.
  */
-gcc_nonnull_all
 PathTraitsUTF8::string
-PathToUTF8(PathTraitsFS::const_pointer path_fs);
+PathToUTF8(PathTraitsFS::string_view path_fs);
 
 /**
  * Convert the path from UTF-8.