diff --git a/contrib/ntp/libparse/clk_hopf6021.c b/contrib/ntp/libparse/clk_hopf6021.c
index b0b0c1ff2a73..a747581b75dc 100644
--- a/contrib/ntp/libparse/clk_hopf6021.c
+++ b/contrib/ntp/libparse/clk_hopf6021.c
@@ -20,6 +20,8 @@
 # include <config.h>
 #endif
 
+#include <ntp_types.h>
+
 #if defined(REFCLOCK) && defined(CLOCK_PARSE) && defined(CLOCK_HOPF6021)
 
 #include "ntp_fp.h"
diff --git a/contrib/ntp/libparse/clk_wharton.c b/contrib/ntp/libparse/clk_wharton.c
index fbe9cc95f5f7..e1ef61d55bdb 100644
--- a/contrib/ntp/libparse/clk_wharton.c
+++ b/contrib/ntp/libparse/clk_wharton.c
@@ -9,6 +9,8 @@
 #include <config.h>
 #endif
 
+#include <ntp_types.h>
+
 #if defined(REFCLOCK) && defined(CLOCK_PARSE) && defined(CLOCK_WHARTON_400A)
 /*
  * Support for WHARTON 400A Series clock + 404.2 serial interface.