diff --git a/message_definitions/v1.0/common.xml b/message_definitions/v1.0/common.xml
index c26a6e676f3..fe66fd543eb 100644
--- a/message_definitions/v1.0/common.xml
+++ b/message_definitions/v1.0/common.xml
@@ -2747,6 +2747,12 @@
       <entry value="10" name="MAV_PARAM_TYPE_REAL64">
         <description>64-bit floating-point</description>
       </entry>
+      <entry value="11" name="MAV_PARAM_TYPE_UNION_INT32">
+        <description>32-bit signed integer carried byte-wise in the param_value field.</description>
+      </entry>
+      <entry value="12" name="MAV_PARAM_TYPE_UNION_UINT32">
+        <description>32-bit unsigned integer carried byte-wise in the param_value field.</description>
+      </entry>
     </enum>
     <enum name="MAV_PARAM_ERROR">
       <wip/>
@@ -2770,6 +2776,12 @@
       <entry value="5" name="MAV_PARAM_ERROR_READ_ONLY">
         <description>Parameter is read-only</description>
       </entry>
+      <entry value="6" name="MAV_PARAM_ERROR_TYPE_UNSUPPORTED">
+        <description>Parameter data type (MAV_PARAM_TYPE) is not supported by flight stack (at all)</description>
+      </entry>
+      <entry value="7" name="MAV_PARAM_ERROR_TYPE_MISMATCH">
+        <description>Parameter type does not match expected type</description>
+      </entry>
     </enum>
     <enum name="MAV_PARAM_EXT_TYPE">
       <description>Specifies the datatype of a MAVLink extended parameter.</description>
diff --git a/message_definitions/v1.0/standard.xml b/message_definitions/v1.0/standard.xml
index df63c937817..f1b8327c206 100644
--- a/message_definitions/v1.0/standard.xml
+++ b/message_definitions/v1.0/standard.xml
@@ -90,6 +90,9 @@
         <wip/>
         <description>Autopilot has a connected gripper. MAVLink Grippers would set MAV_TYPE_GRIPPER instead.</description>
       </entry>
+      <entry value="2097152" name="MAV_PROTOCOL_CAPABILITY_PARAM_UNION_INT32">
+        <description>Component accepts PARAM_SET and emits PARAM_VALUE with the byte-wise MAV_PARAM_TYPE_UNION_INT32/MAV_PARAM_TYPE_UNION_UINT32 types for lossless transport of 32-bit integer parameter values that are not exactly representable as a 32-bit float. Only meaningful in combination with MAV_PROTOCOL_CAPABILITY_PARAM_ENCODE_C_CAST: byte-wise encoded systems are already lossless. Ground stations should should send the union types to a component that does not advertise this capability.</description>
+      </entry>
     </enum>
     <enum name="FIRMWARE_VERSION_TYPE">
       <description>These values define the type of firmware release.  These values indicate the first version or release of this type.  For example the first alpha release would be 64, the second would be 65.</description>
diff --git a/pymavlink b/pymavlink
index ec06837a506..c065f0feb0c 160000
--- a/pymavlink
+++ b/pymavlink
@@ -1 +1 @@
-Subproject commit ec06837a50688b5974094876c3c9d1b8bf86629d
+Subproject commit c065f0feb0ceacc35a8344945a46924b0a8a1a5a