diff --git a/spa/include/spa/support/plugin.h b/spa/include/spa/support/plugin.h
index 4b49306dd..c7e83a82a 100644
--- a/spa/include/spa/support/plugin.h
+++ b/spa/include/spa/support/plugin.h
@@ -107,9 +107,14 @@ struct spa_handle_factory {
 	 */
 	const struct spa_dict *info;
 	/**
-	 * The size of handles from this factory
+	 * Get the size of handles from this factory.
+	 *
+	 * \param factory a spa_handle_factory
+	 * \param params extra parameters that determine the size of the
+	 * handle.
 	 */
-	const size_t size;
+	size_t (*get_size) (const struct spa_handle_factory *factory,
+			    const struct spa_dict *params);
 
 	/**
 	 * Initialize an instance of this factory. The caller should allocate
@@ -150,6 +155,7 @@ struct spa_handle_factory {
 				    uint32_t *index);
 };
 
+#define spa_handle_factory_get_size(h,...)		(h)->get_size((h),__VA_ARGS__)
 #define spa_handle_factory_init(h,...)			(h)->init((h),__VA_ARGS__)
 #define spa_handle_factory_enum_interface_info(h,...)	(h)->enum_interface_info((h),__VA_ARGS__)
 
diff --git a/spa/plugins/alsa/alsa-monitor.c b/spa/plugins/alsa/alsa-monitor.c
index 08a4adfae..0c5d43714 100644
--- a/spa/plugins/alsa/alsa-monitor.c
+++ b/spa/plugins/alsa/alsa-monitor.c
@@ -479,6 +479,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -545,7 +552,7 @@ const struct spa_handle_factory spa_alsa_monitor_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/alsa/alsa-sink.c b/spa/plugins/alsa/alsa-sink.c
index 0e4167dfb..b75a670f2 100644
--- a/spa/plugins/alsa/alsa-sink.c
+++ b/spa/plugins/alsa/alsa-sink.c
@@ -658,6 +658,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct state);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle, const struct spa_dict *info, const struct spa_support *support, uint32_t n_support)
@@ -754,7 +761,7 @@ const struct spa_handle_factory spa_alsa_sink_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	&info,
-	sizeof(struct state),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/alsa/alsa-source.c b/spa/plugins/alsa/alsa-source.c
index 808dd6100..150baebff 100644
--- a/spa/plugins/alsa/alsa-source.c
+++ b/spa/plugins/alsa/alsa-source.c
@@ -713,6 +713,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct state);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -812,7 +819,7 @@ const struct spa_handle_factory spa_alsa_source_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	&info,
-	sizeof(struct state),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/audioconvert/audioconvert.c b/spa/plugins/audioconvert/audioconvert.c
index bdd8f75c8..a3ff89688 100644
--- a/spa/plugins/audioconvert/audioconvert.c
+++ b/spa/plugins/audioconvert/audioconvert.c
@@ -898,6 +898,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -974,7 +981,7 @@ const struct spa_handle_factory spa_audioconvert_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/audioconvert/channelmix.c b/spa/plugins/audioconvert/channelmix.c
index b08eb7fe0..c6f79db01 100644
--- a/spa/plugins/audioconvert/channelmix.c
+++ b/spa/plugins/audioconvert/channelmix.c
@@ -871,6 +871,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -947,7 +954,7 @@ const struct spa_handle_factory spa_channelmix_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/audioconvert/fmtconvert.c b/spa/plugins/audioconvert/fmtconvert.c
index 51110b28d..fb8d49c39 100644
--- a/spa/plugins/audioconvert/fmtconvert.c
+++ b/spa/plugins/audioconvert/fmtconvert.c
@@ -927,6 +927,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -1003,7 +1010,7 @@ const struct spa_handle_factory spa_fmtconvert_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/audiomixer/audiomixer.c b/spa/plugins/audiomixer/audiomixer.c
index f8bc5c2fd..af80e6cbc 100644
--- a/spa/plugins/audiomixer/audiomixer.c
+++ b/spa/plugins/audiomixer/audiomixer.c
@@ -1114,6 +1114,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -1187,7 +1194,7 @@ const struct spa_handle_factory spa_audiomixer_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/audiotestsrc/audiotestsrc.c b/spa/plugins/audiotestsrc/audiotestsrc.c
index 50e43f64f..ee3f90143 100644
--- a/spa/plugins/audiotestsrc/audiotestsrc.c
+++ b/spa/plugins/audiotestsrc/audiotestsrc.c
@@ -1146,6 +1146,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -1250,7 +1257,7 @@ const struct spa_handle_factory spa_audiotestsrc_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	&info,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/bluez5/a2dp-sink.c b/spa/plugins/bluez5/a2dp-sink.c
index 65df300bd..df74e2056 100644
--- a/spa/plugins/bluez5/a2dp-sink.c
+++ b/spa/plugins/bluez5/a2dp-sink.c
@@ -1340,6 +1340,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -1439,7 +1446,7 @@ struct spa_handle_factory spa_a2dp_sink_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	&info,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/bluez5/bluez5-monitor.c b/spa/plugins/bluez5/bluez5-monitor.c
index 2e65f1a1b..b0f15c434 100644
--- a/spa/plugins/bluez5/bluez5-monitor.c
+++ b/spa/plugins/bluez5/bluez5-monitor.c
@@ -1180,6 +1180,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct spa_bt_monitor);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -1257,7 +1264,7 @@ static const struct spa_handle_factory spa_bluez5_monitor_factory = {
 	SPA_VERSION_MONITOR,
 	NAME,
 	NULL,
-	sizeof(struct spa_bt_monitor),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/support/dbus.c b/spa/plugins/support/dbus.c
index 8f9787352..3e1db92a0 100644
--- a/spa/plugins/support/dbus.c
+++ b/spa/plugins/support/dbus.c
@@ -353,6 +353,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -426,7 +433,7 @@ static const struct spa_handle_factory dbus_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/support/logger.c b/spa/plugins/support/logger.c
index ce5deafd0..b514ec3aa 100644
--- a/spa/plugins/support/logger.c
+++ b/spa/plugins/support/logger.c
@@ -180,6 +180,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -259,7 +266,7 @@ static const struct spa_handle_factory logger_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/support/loop.c b/spa/plugins/support/loop.c
index c73cdfbca..0dd7cc97d 100644
--- a/spa/plugins/support/loop.c
+++ b/spa/plugins/support/loop.c
@@ -690,6 +690,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -766,7 +773,7 @@ static const struct spa_handle_factory loop_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info
 };
diff --git a/spa/plugins/support/mapper.c b/spa/plugins/support/mapper.c
index b1f5ba0ed..f2a40335b 100644
--- a/spa/plugins/support/mapper.c
+++ b/spa/plugins/support/mapper.c
@@ -154,6 +154,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -206,7 +213,7 @@ static const struct spa_handle_factory type_map_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/test/fakesink.c b/spa/plugins/test/fakesink.c
index fecfd7003..0d63361cf 100644
--- a/spa/plugins/test/fakesink.c
+++ b/spa/plugins/test/fakesink.c
@@ -840,6 +840,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -929,7 +936,7 @@ const struct spa_handle_factory spa_fakesink_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/test/fakesrc.c b/spa/plugins/test/fakesrc.c
index 8540fa1d6..a286794d3 100644
--- a/spa/plugins/test/fakesrc.c
+++ b/spa/plugins/test/fakesrc.c
@@ -875,6 +875,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -964,7 +971,7 @@ const struct spa_handle_factory spa_fakesrc_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/v4l2/v4l2-monitor.c b/spa/plugins/v4l2/v4l2-monitor.c
index 50789ff3a..12a6c1270 100644
--- a/spa/plugins/v4l2/v4l2-monitor.c
+++ b/spa/plugins/v4l2/v4l2-monitor.c
@@ -337,6 +337,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -403,7 +410,7 @@ const struct spa_handle_factory spa_v4l2_monitor_factory = {
 	SPA_VERSION_MONITOR,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/v4l2/v4l2-source.c b/spa/plugins/v4l2/v4l2-source.c
index 720a43322..27394f01c 100644
--- a/spa/plugins/v4l2/v4l2-source.c
+++ b/spa/plugins/v4l2/v4l2-source.c
@@ -975,6 +975,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -1065,7 +1072,7 @@ const struct spa_handle_factory spa_v4l2_source_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/videotestsrc/videotestsrc.c b/spa/plugins/videotestsrc/videotestsrc.c
index db9066076..814cb9217 100644
--- a/spa/plugins/videotestsrc/videotestsrc.c
+++ b/spa/plugins/videotestsrc/videotestsrc.c
@@ -986,6 +986,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -1085,7 +1092,7 @@ const struct spa_handle_factory spa_videotestsrc_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	&info,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/plugins/volume/volume.c b/spa/plugins/volume/volume.c
index f772e5d34..ac100080d 100644
--- a/spa/plugins/volume/volume.c
+++ b/spa/plugins/volume/volume.c
@@ -899,6 +899,13 @@ static int impl_clear(struct spa_handle *handle)
 	return 0;
 }
 
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
 static int
 impl_init(const struct spa_handle_factory *factory,
 	  struct spa_handle *handle,
@@ -971,7 +978,7 @@ const struct spa_handle_factory spa_volume_factory = {
 	SPA_VERSION_HANDLE_FACTORY,
 	NAME,
 	NULL,
-	sizeof(struct impl),
+	impl_get_size,
 	impl_init,
 	impl_enum_interface_info,
 };
diff --git a/spa/tests/test-bluez5.c b/spa/tests/test-bluez5.c
index abea5fe9d..29a54da52 100644
--- a/spa/tests/test-bluez5.c
+++ b/spa/tests/test-bluez5.c
@@ -188,7 +188,7 @@ static int get_handle(struct data *data,
 		if (strcmp(factory->name, name))
 			continue;
 
-		*handle = calloc(1, factory->size);
+		*handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res = spa_handle_factory_init(factory, *handle, NULL,
 						   data->support,
 						   data->n_support)) < 0) {
diff --git a/spa/tests/test-control.c b/spa/tests/test-control.c
index 6450d92a5..3ee26c4bd 100644
--- a/spa/tests/test-control.c
+++ b/spa/tests/test-control.c
@@ -216,7 +216,7 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 		if (strcmp(factory->name, name))
 			continue;
 
-		handle = calloc(1, factory->size);
+		handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res =
 		     spa_handle_factory_init(factory, handle, NULL, data->support,
 					     data->n_support)) < 0) {
diff --git a/spa/tests/test-convert.c b/spa/tests/test-convert.c
index bb2505739..c963b09f4 100644
--- a/spa/tests/test-convert.c
+++ b/spa/tests/test-convert.c
@@ -183,7 +183,7 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 		if (strcmp(factory->name, name))
 			continue;
 
-		handle = calloc(1, factory->size);
+		handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res =
 		     spa_handle_factory_init(factory, handle, NULL, data->support,
 					     data->n_support)) < 0) {
diff --git a/spa/tests/test-convert2.c b/spa/tests/test-convert2.c
index 87e62f1e8..54a53cba7 100644
--- a/spa/tests/test-convert2.c
+++ b/spa/tests/test-convert2.c
@@ -144,7 +144,7 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 		if (strcmp(factory->name, name))
 			continue;
 
-		handle = calloc(1, factory->size);
+		handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res =
 		     spa_handle_factory_init(factory, handle, NULL, data->support,
 					     data->n_support)) < 0) {
diff --git a/spa/tests/test-graph.c b/spa/tests/test-graph.c
index f65e3cb71..6b003b9ec 100644
--- a/spa/tests/test-graph.c
+++ b/spa/tests/test-graph.c
@@ -213,7 +213,7 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 		if (strcmp(factory->name, name))
 			continue;
 
-		handle = calloc(1, factory->size);
+		handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res =
 		     spa_handle_factory_init(factory, handle, NULL, data->support,
 					     data->n_support)) < 0) {
diff --git a/spa/tests/test-mixer.c b/spa/tests/test-mixer.c
index 01784eb2a..d52d4eb29 100644
--- a/spa/tests/test-mixer.c
+++ b/spa/tests/test-mixer.c
@@ -233,7 +233,7 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 		if (strcmp(factory->name, name))
 			continue;
 
-		handle = calloc(1, factory->size);
+		handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res =
 		     spa_handle_factory_init(factory, handle, NULL, data->support,
 					     data->n_support)) < 0) {
diff --git a/spa/tests/test-perf.c b/spa/tests/test-perf.c
index adc59f17a..890c78983 100644
--- a/spa/tests/test-perf.c
+++ b/spa/tests/test-perf.c
@@ -209,7 +209,7 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 		if (strcmp(factory->name, name))
 			continue;
 
-		handle = calloc(1, factory->size);
+		handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res =
 		     spa_handle_factory_init(factory, handle, NULL, data->support,
 					     data->n_support)) < 0) {
diff --git a/spa/tests/test-ringbuffer.c b/spa/tests/test-ringbuffer.c
index 5816aa805..e39703c1f 100644
--- a/spa/tests/test-ringbuffer.c
+++ b/spa/tests/test-ringbuffer.c
@@ -187,7 +187,7 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 		if (strcmp(factory->name, name))
 			continue;
 
-		handle = calloc(1, factory->size);
+		handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res =
 		     spa_handle_factory_init(factory, handle, NULL, data->support,
 					     data->n_support)) < 0) {
diff --git a/spa/tests/test-v4l2.c b/spa/tests/test-v4l2.c
index 0e67f1bf1..57f37114b 100644
--- a/spa/tests/test-v4l2.c
+++ b/spa/tests/test-v4l2.c
@@ -155,7 +155,7 @@ static int make_node(struct data *data, struct spa_node **node, const char *lib,
 		if (strcmp(factory->name, name))
 			continue;
 
-		handle = calloc(1, factory->size);
+		handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 		if ((res =
 		     spa_handle_factory_init(factory, handle, NULL, data->support,
 					     data->n_support)) < 0) {
diff --git a/spa/tools/spa-inspect.c b/spa/tools/spa-inspect.c
index e25fbf12d..668b07a9b 100644
--- a/spa/tools/spa-inspect.c
+++ b/spa/tools/spa-inspect.c
@@ -210,7 +210,7 @@ static void inspect_factory(struct data *data, const struct spa_handle_factory *
 		printf(" interface: '%s'\n", info->type);
 	}
 
-	handle = calloc(1, factory->size);
+	handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 	if ((res =
 	     spa_handle_factory_init(factory, handle, NULL, data->support, data->n_support)) < 0) {
 		printf("can't make factory instance: %d\n", res);
diff --git a/spa/tools/spa-monitor.c b/spa/tools/spa-monitor.c
index d4afeafda..9e252acaf 100644
--- a/spa/tools/spa-monitor.c
+++ b/spa/tools/spa-monitor.c
@@ -224,7 +224,7 @@ int main(int argc, char *argv[])
 				struct spa_handle *handle;
 				void *interface;
 
-				handle = calloc(1, factory->size);
+				handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 				if ((res =
 				     spa_handle_factory_init(factory, handle, NULL, data.support,
 							     data.n_support)) < 0) {
diff --git a/src/modules/module-mixer.c b/src/modules/module-mixer.c
index 06f2991b9..4fb14208d 100644
--- a/src/modules/module-mixer.c
+++ b/src/modules/module-mixer.c
@@ -109,7 +109,10 @@ static struct pw_node *make_node(struct impl *impl, struct pw_properties *proper
 
 	support = pw_core_get_support(impl->core, &n_support);
 
-	handle = calloc(1, impl->factory->size);
+        handle = calloc(1, spa_handle_factory_get_size(impl->factory, NULL));
+	if (handle == NULL)
+		goto no_mem;
+
 	if ((res = spa_handle_factory_init(impl->factory,
 					   handle,
 					   NULL, support, n_support)) < 0) {
@@ -140,6 +143,7 @@ static struct pw_node *make_node(struct impl *impl, struct pw_properties *proper
 	spa_handle_clear(handle);
       init_failed:
 	free(handle);
+      no_mem:
 	return NULL;
 }
 
diff --git a/src/modules/spa/spa-monitor.c b/src/modules/spa/spa-monitor.c
index ea84555f8..f3ec7c2d6 100644
--- a/src/modules/spa/spa-monitor.c
+++ b/src/modules/spa/spa-monitor.c
@@ -103,7 +103,7 @@ static void add_item(struct pw_spa_monitor *this, struct spa_pod *item)
 
 	support = pw_core_get_support(impl->core, &n_support);
 
-	handle = calloc(1, factory->size);
+        handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
 	if ((res = spa_handle_factory_init(factory,
 					   handle,
 					   &props->dict,
@@ -292,8 +292,12 @@ struct pw_spa_monitor *pw_spa_monitor_load(struct pw_core *core,
 		if (strcmp(factory->name, factory_name) == 0)
 			break;
 	}
+	handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
+	if (handle == NULL)
+		goto no_mem;
+
 	support = pw_core_get_support(core, &n_support);
-	handle = calloc(1, factory->size);
+
 	if ((res = spa_handle_factory_init(factory,
 					   handle, NULL, support, n_support)) < 0) {
 		pw_log_error("can't make factory instance: %d", res);
@@ -345,6 +349,7 @@ struct pw_spa_monitor *pw_spa_monitor_load(struct pw_core *core,
 	spa_handle_clear(handle);
       init_failed:
 	free(handle);
+      no_mem:
       enum_failed:
       no_symbol:
 	dlclose(hnd);
diff --git a/src/modules/spa/spa-node.c b/src/modules/spa/spa-node.c
index 1d2e7bdf8..38120fa3f 100644
--- a/src/modules/spa/spa-node.c
+++ b/src/modules/spa/spa-node.c
@@ -279,7 +279,10 @@ struct pw_node *pw_spa_node_load(struct pw_core *core,
 
 	support = pw_core_get_support(core, &n_support);
 
-	handle = calloc(1, factory->size);
+        handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
+	if (handle == NULL)
+		goto no_mem;
+
 	if ((res = spa_handle_factory_init(factory,
 					   handle,
 					   properties ? &properties->dict : NULL,
@@ -319,6 +322,7 @@ struct pw_node *pw_spa_node_load(struct pw_core *core,
       init_failed:
 	free(handle);
       enum_failed:
+      no_mem:
       no_symbol:
 	dlclose(hnd);
       open_failed:
diff --git a/src/pipewire/loop.c b/src/pipewire/loop.c
index 6944125fb..e05cafdc2 100644
--- a/src/pipewire/loop.c
+++ b/src/pipewire/loop.c
@@ -64,7 +64,7 @@ struct pw_loop *pw_loop_new(struct pw_properties *properties)
 	if (factory == NULL)
 		return NULL;
 
-	impl = calloc(1, sizeof(struct impl) + factory->size);
+	impl = calloc(1, sizeof(struct impl) + spa_handle_factory_get_size(factory, NULL));
 	if (impl == NULL)
 		return NULL;
 
diff --git a/src/pipewire/pipewire.c b/src/pipewire/pipewire.c
index b66b44eeb..2de855af6 100644
--- a/src/pipewire/pipewire.c
+++ b/src/pipewire/pipewire.c
@@ -107,7 +107,7 @@ load_interface(struct support_info *info,
 	if (factory == NULL)
 		goto not_found;
 
-        handle = calloc(1, factory->size);
+        handle = calloc(1, spa_handle_factory_get_size(factory, NULL));
         if ((res = spa_handle_factory_init(factory,
                                            handle, NULL, info->support, info->n_support)) < 0) {
                 fprintf(stderr, "can't make factory instance: %d\n", res);