diff --git a/src/gswe-moment.c b/src/gswe-moment.c
index cc8ef5e..78dfa85 100644
--- a/src/gswe-moment.c
+++ b/src/gswe-moment.c
@@ -974,7 +974,7 @@ gswe_moment_get_moon_phase(GsweMoment *moment, GError **err)
         return moment->priv->moon_phase;
     }
 
-    gswe_moon_phase_data_calculate_by_timestamp(moment->priv->timestamp, err);
+    gswe_moon_phase_data_calculate_by_timestamp(moment->priv->moon_phase, moment->priv->timestamp, err);
 
     if (!err || !*err) {
         moment->priv->moon_phase_revision = moment->priv->revision;
diff --git a/src/gswe-moon-phase-data.h b/src/gswe-moon-phase-data.h
index 754b7f3..68c943f 100644
--- a/src/gswe-moon-phase-data.h
+++ b/src/gswe-moon-phase-data.h
@@ -21,6 +21,7 @@
 #include <glib-object.h>
 
 #include "gswe-types.h"
+#include "gswe-timestamp.h"
 
 G_BEGIN_DECLS