diff --git a/src/gswe-moment.c b/src/gswe-moment.c
index b8b6937..8d4a3cb 100644
--- a/src/gswe-moment.c
+++ b/src/gswe-moment.c
@@ -392,11 +392,7 @@ gswe_moment_get_house_system(GsweMoment *moment)
  *
  * Returns: a GQuark used to identify errors coming from the SWE-GLib API
  */
-GQuark
-gswe_moment_error_quark(void)
-{
-    return g_quark_from_static_string("swe-glib-gswe-moment-error");
-}
+G_DEFINE_QUARK(gswe-moment-error-quark, gswe_moment_error);
 
 /**
  * gswe_moment_new:
diff --git a/src/gswe-timestamp.c b/src/gswe-timestamp.c
index 5a351f4..0f138ad 100644
--- a/src/gswe-timestamp.c
+++ b/src/gswe-timestamp.c
@@ -638,11 +638,7 @@ gswe_timestamp_get_julian_day(GsweTimestamp *timestamp, GError **err)
     return timestamp->priv->julian_day;
 }
 
-GQuark
-gswe_timestamp_error_quark(void)
-{
-    return g_quark_from_static_string("swe-glib-gswe-timestamp-error");
-}
+G_DEFINE_QUARK(gswe-timestamp-error-quark, gswe_timestamp_error);
 
 /**
  * gswe_timestamp_new: