diff --git a/commit-slab-impl.h b/commit-slab-impl.h
index ac1e6d409a..5c0eb91a5d 100644
--- a/commit-slab-impl.h
+++ b/commit-slab-impl.h
@@ -1,10 +1,10 @@
 #ifndef COMMIT_SLAB_IMPL_H
 #define COMMIT_SLAB_IMPL_H
 
-#define MAYBE_UNUSED __attribute__((__unused__))
+#include "git-compat-util.h"
 
 #define implement_static_commit_slab(slabname, elemtype) \
-	implement_commit_slab(slabname, elemtype, static MAYBE_UNUSED)
+	implement_commit_slab(slabname, elemtype, MAYBE_UNUSED static)
 
 #define implement_shared_commit_slab(slabname, elemtype) \
 	implement_commit_slab(slabname, elemtype, )
diff --git a/git-compat-util.h b/git-compat-util.h
index 48c955541e..8121b73b4a 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -408,6 +408,8 @@ static inline char *git_find_last_dir_sep(const char *path)
 #define LAST_ARG_MUST_BE_NULL
 #endif
 
+#define MAYBE_UNUSED __attribute__((__unused__))
+
 #include "compat/bswap.h"
 
 #include "wildmatch.h"