diff --git a/elf/tst-tls20.c b/elf/tst-tls20.c
index 18067e6b0a..200dacb748 100644
--- a/elf/tst-tls20.c
+++ b/elf/tst-tls20.c
@@ -19,6 +19,7 @@
 #include <array_length.h>
 #include <dlfcn.h>
 #include <pthread.h>
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>