diff --git a/libraries/base/include/HsBase.h b/libraries/base/include/HsBase.h
index cfe046426d8e2e366cf415484dfb6d13259636fc..cbbccbf458ebcba4e85f4f02d0e22521999fa967 100644
--- a/libraries/base/include/HsBase.h
+++ b/libraries/base/include/HsBase.h
@@ -100,7 +100,7 @@
 #elif HAVE_STDINT_H
 # include <stdint.h>
 #endif
-#if HAVE_CLOCK_GETTIME
+#ifdef HAVE_CLOCK_GETTIME
 # ifdef _POSIX_MONOTONIC_CLOCK
 #  define CLOCK_ID CLOCK_MONOTONIC
 # else