diff --git a/sysdeps/unix/sysv/linux/alpha/bits/time.h b/sysdeps/unix/sysv/linux/alpha/bits/time.h
index b9d9f3f8d5..93c01c09c0 100644
--- a/sysdeps/unix/sysv/linux/alpha/bits/time.h
+++ b/sysdeps/unix/sysv/linux/alpha/bits/time.h
@@ -36,8 +36,9 @@
 #  ifndef __STRICT_ANSI__
 /* Even though CLOCKS_PER_SEC has such a strange value CLK_TCK
    presents the real value for clock ticks per second for the system.  */
+#   include <bits/types.h>
 extern long int __sysconf (int);
-#   define CLK_TCK (__sysconf (2))	/* 2 is _SC_CLK_TCK */
+#   define CLK_TCK ((__clock_t) __sysconf (2))	/* 2 is _SC_CLK_TCK */
 #  endif
 
 #  ifdef __USE_POSIX199309