3 files changed, 9 insertions, 8 deletions
diff --git a/src/uca-camera.c b/src/uca-camera.c
index 8bb7201..27af765 100644
--- a/src/uca-camera.c
+++ b/src/uca-camera.c
@@ -135,8 +135,12 @@ struct _UcaCameraPrivate {
 static void
 uca_camera_set_property_unit (GParamSpec *pspec, UcaUnit unit)
 {
-    if (g_param_spec_get_qdata (pspec, UCA_UNIT_QUARK) != NULL)
-        g_warning ("::%s already has a unit", pspec->name);
+    UcaUnit old_unit;
+
+    old_unit = (UcaUnit) GPOINTER_TO_INT (g_param_spec_get_qdata (pspec, UCA_UNIT_QUARK));
+
+    if (old_unit != unit && old_unit != UCA_UNIT_NA)
+        g_warning ("::%s already has a different unit", pspec->name);
     else
         g_param_spec_set_qdata (pspec, UCA_UNIT_QUARK, GINT_TO_POINTER (unit));
 }
diff --git a/src/uca-camera.h b/src/uca-camera.h
index daa2bda..f4030d6 100644
--- a/src/uca-camera.h
+++ b/src/uca-camera.h
@@ -51,7 +51,7 @@ typedef enum {
 } UcaCameraTrigger;
 
 typedef enum {
-    UCA_UNIT_NA,
+    UCA_UNIT_NA = 0,
     UCA_UNIT_METER,
     UCA_UNIT_SECOND,
     UCA_UNIT_PIXEL,
diff --git a/test/test-mock.c b/test/test-mock.c
index de1e18d..d1dcf3a 100644
--- a/test/test-mock.c
+++ b/test/test-mock.c
@@ -224,11 +224,7 @@ test_signal (Fixture *fixture, gconstpointer data)
 static void
 test_overwriting_units (Fixture *fixture, gconstpointer data)
 {
-    UcaUnit unit;
-
-    uca_camera_register_unit (fixture->camera, "frames-per-second", UCA_UNIT_PIXEL);
-    unit = uca_camera_get_unit (fixture->camera, "frames-per-second");
-    g_assert (unit != UCA_UNIT_PIXEL);
+    uca_camera_register_unit (fixture->camera, "sensor-width", UCA_UNIT_PIXEL);
 }
 
 int main (int argc, char *argv[])
@@ -249,6 +245,7 @@ int main (int argc, char *argv[])
     g_test_add ("/properties/binnings", Fixture, NULL, fixture_setup, test_binnings_properties, fixture_teardown);
     g_test_add ("/properties/frames-per-second", Fixture, NULL, fixture_setup, test_fps_property, fixture_teardown);
     g_test_add ("/properties/units", Fixture, NULL, fixture_setup, test_property_units, fixture_teardown);
+    g_test_add ("/properties/units/overwrite", Fixture, NULL, fixture_setup, test_overwriting_units, fixture_teardown);
     g_test_add ("/signal", Fixture, NULL, fixture_setup, test_signal, fixture_teardown);
 
     return g_test_run ();