diff --git a/plugins/synapticsmst/synapticsmst-common.c b/plugins/synapticsmst/synapticsmst-common.c
index 0cef39cb5..35dfe219a 100644
--- a/plugins/synapticsmst/synapticsmst-common.c
+++ b/plugins/synapticsmst/synapticsmst-common.c
@@ -57,7 +57,7 @@ synapticsmst_common_aux_node_read (SynapticsMSTConnection *connection,
 
 static guint8
 synapticsmst_common_aux_node_write (SynapticsMSTConnection *connection,
-				    gint offset, gint *buf, gint length)
+				    gint offset, const gint *buf, gint length)
 {
 	if (lseek (connection->fd, offset, SEEK_SET) != offset)
 		return DPCD_SEEK_FAIL;
@@ -106,7 +106,7 @@ synapticsmst_common_read_dpcd (SynapticsMSTConnection *connection,
 guint8
 synapticsmst_common_write_dpcd (SynapticsMSTConnection *connection,
 				gint offset,
-				gint *buf,
+				const gint *buf,
 				gint length)
 {
 	if (connection->layer && connection->remain_layer) {
@@ -128,7 +128,7 @@ synapticsmst_common_rc_set_command (SynapticsMSTConnection *connection,
 				    gint rc_cmd,
 				    gint length,
 				    gint offset,
-				    guint8 *buf)
+				    const guint8 *buf)
 {
 	guint8 rc = 0;
 	gint cur_offset = offset;
diff --git a/plugins/synapticsmst/synapticsmst-common.h b/plugins/synapticsmst/synapticsmst-common.h
index a7f2220bd..9c4be5e49 100644
--- a/plugins/synapticsmst/synapticsmst-common.h
+++ b/plugins/synapticsmst/synapticsmst-common.h
@@ -91,14 +91,14 @@ guint8		 synapticsmst_common_read_dpcd 			(SynapticsMSTConnection *connection,
 
 guint8		 synapticsmst_common_write_dpcd 		(SynapticsMSTConnection *connection,
 								 gint	 offset,
-								 gint	*buf,
+								 const gint *buf,
 								 gint	 length);
 
 guint8		 synapticsmst_common_rc_set_command 		(SynapticsMSTConnection *connection,
 								 gint	 rc_cmd,
 								 gint	 length,
 								 gint	 offset,
-								 guint8	*buf);
+								 const guint8	*buf);
 
 guint8		 synapticsmst_common_rc_get_command 		(SynapticsMSTConnection *connection,
 								 gint	 rc_cmd,
diff --git a/plugins/thunderbolt/fu-plugin-thunderbolt.c b/plugins/thunderbolt/fu-plugin-thunderbolt.c
index 0ecf36046..ee5424b16 100644
--- a/plugins/thunderbolt/fu-plugin-thunderbolt.c
+++ b/plugins/thunderbolt/fu-plugin-thunderbolt.c
@@ -410,7 +410,7 @@ fu_plugin_thunderbolt_uevent_cb (GUdevClient *gudev_client,
 		devpath = fu_plugin_thunderbolt_find_devpath (plugin, udev_device);
 		if (devpath != NULL) {
 			g_debug ("potentially removing tbt device");
-			g_ptr_array_remove (data->devpaths, devpath);
+			g_ptr_array_remove (data->devpaths, (gpointer) devpath);
 			fu_plugin_thunderbolt_schedule_rescan (plugin);
 		}
 		return;