diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 33af675..3c07555 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -19,6 +19,7 @@
 #include "vdso.h"
 #include "probe-file.h"
 
+#include "sane_ctype.h"
 
 static bool no_buildid_cache;