diff --git a/cairo/pattern.c b/cairo/pattern.c
index de6af809..278f79f1 100644
--- a/cairo/pattern.c
+++ b/cairo/pattern.c
@@ -1018,6 +1018,7 @@ _raster_source_release_func (cairo_pattern_t *pattern,
     result = NULL;
     goto error;
   }
+  Py_DECREF (result);
 
   Py_DECREF (pysurface);
   PyGILState_Release (gstate);
diff --git a/cairo/surface.c b/cairo/surface.c
index b7b36f29..7909d39c 100644
--- a/cairo/surface.c
+++ b/cairo/surface.c
@@ -503,7 +503,7 @@ surface_set_mime_data (PycairoSurface *o, PyObject *args) {
   mime_intern = PyUnicode_InternFromString (mime_type);
   surface_capsule = PyCapsule_New(o->surface, NULL, NULL);
   view_capsule = PyCapsule_New(view, NULL, NULL);
-  user_data = Py_BuildValue("(NNOO)", surface_capsule, view_capsule, obj, mime_intern);
+  user_data = Py_BuildValue("(NNON)", surface_capsule, view_capsule, obj, mime_intern);
   if (user_data == NULL) {
     PyBuffer_Release (view);
     PyMem_Free (view);
@@ -558,6 +558,7 @@ surface_get_mime_data (PycairoSurface *o, PyObject *args) {
   mime_intern = PyUnicode_InternFromString (mime_type);
   user_data = cairo_surface_get_user_data(
     o->surface, (cairo_user_data_key_t *)mime_intern);
+  Py_DECREF(mime_intern);
 
   if (user_data == NULL) {
     /* In case the mime data wasn't set through the Python API just copy it */