diff --git a/src/tag/FixString.cxx b/src/tag/FixString.cxx
index 23a872068..f2069f033 100644
--- a/src/tag/FixString.cxx
+++ b/src/tag/FixString.cxx
@@ -29,7 +29,7 @@
 
 #include <stdlib.h>
 
-gcc_pure
+[[gnu::pure]]
 static const char *
 FindInvalidUTF8(const char *p, const char *const end) noexcept
 {
@@ -116,7 +116,7 @@ clear_non_printable(StringView src)
 	return { dest, src.size };
 }
 
-gcc_pure
+[[gnu::pure]]
 static bool
 IsSafe(StringView s) noexcept
 {
diff --git a/src/tag/FixString.hxx b/src/tag/FixString.hxx
index 819c72d3b..881763212 100644
--- a/src/tag/FixString.hxx
+++ b/src/tag/FixString.hxx
@@ -20,12 +20,9 @@
 #ifndef MPD_TAG_STRING_HXX
 #define MPD_TAG_STRING_HXX
 
-#include "util/Compiler.h"
-
 struct StringView;
 template<typename T> struct WritableBuffer;
 
-gcc_nonnull_all
 WritableBuffer<char>
 FixTagString(StringView p);