diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 96b1f06c2..c2d00a14d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -272,7 +272,7 @@ jobs:
           submodules: true
       - name: Check docs
         run: |
-          python3 -m pip install sphinx
+          python3 -m pip install sphinx==7.2.6
           python3 -m pip install --verbose .
           ./scripts/make-docs.py
 
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index a0ca31620..1a28f6464 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -20,7 +20,7 @@ jobs:
 
       - name: Update docs branch
         run: |
-          python3 -m pip install sphinx
+          python3 -m pip install sphinx==7.2.6
           python3 -m pip install --verbose .
           ./scripts/make-docs.py
 
diff --git a/awscrt/mqtt.py b/awscrt/mqtt.py
index 5a96f5632..7529168ea 100644
--- a/awscrt/mqtt.py
+++ b/awscrt/mqtt.py
@@ -444,11 +444,15 @@ def _on_connection_resumed(self, return_code, session_present):
 
     def _ws_handshake_transform(self, http_request_binding, http_headers_binding, native_userdata):
         if self._ws_handshake_transform_cb is None:
-            _awscrt.mqtt_ws_handshake_transform_complete(None, native_userdata)
+            _awscrt.mqtt_ws_handshake_transform_complete(None, native_userdata, 0)
             return
 
         def _on_complete(f):
-            _awscrt.mqtt_ws_handshake_transform_complete(f.exception(), native_userdata)
+            error_code = 0
+            hs_exception = f.exception()
+            if isinstance(hs_exception, awscrt.exceptions.AwsCrtError):
+                error_code = hs_exception.code
+            _awscrt.mqtt_ws_handshake_transform_complete(f.exception(), native_userdata, error_code)
 
         future = Future()
         future.add_done_callback(_on_complete)
diff --git a/awscrt/mqtt5.py b/awscrt/mqtt5.py
index 80dd0d002..4f8bff98d 100644
--- a/awscrt/mqtt5.py
+++ b/awscrt/mqtt5.py
@@ -1391,11 +1391,15 @@ def __init__(self, client_options: ClientOptions):
 
     def _ws_handshake_transform(self, http_request_binding, http_headers_binding, native_userdata):
         if self._ws_handshake_transform_cb is None:
-            _awscrt.mqtt5_ws_handshake_transform_complete(None, native_userdata)
+            _awscrt.mqtt5_ws_handshake_transform_complete(None, native_userdata, 0)
             return
 
         def _on_complete(f):
-            _awscrt.mqtt5_ws_handshake_transform_complete(f.exception(), native_userdata)
+            error_code = 0
+            hs_exception = f.exception()
+            if isinstance(hs_exception, exceptions.AwsCrtError):
+                error_code = hs_exception.code
+            _awscrt.mqtt5_ws_handshake_transform_complete(f.exception(), native_userdata, error_code)
 
         future = Future()
         future.add_done_callback(_on_complete)
diff --git a/source/mqtt5_client.c b/source/mqtt5_client.c
index 92e2b1ea1..eddc5ab7f 100644
--- a/source/mqtt5_client.c
+++ b/source/mqtt5_client.c
@@ -711,13 +711,13 @@ PyObject *aws_py_mqtt5_ws_handshake_transform_complete(PyObject *self, PyObject
 
     PyObject *exception_py;
     PyObject *ws_transform_capsule;
-    if (!PyArg_ParseTuple(args, "OO", &exception_py, &ws_transform_capsule)) {
+    int error_code = AWS_ERROR_SUCCESS;
+    if (!PyArg_ParseTuple(args, "OOi", &exception_py, &ws_transform_capsule, &error_code)) {
         return NULL;
     }
 
-    int error_code = AWS_ERROR_SUCCESS;
-    if (exception_py != Py_None) {
-        /* TODO: Translate Python exception to aws error. In the meantime here's a catch-all. */
+    if (exception_py != Py_None && error_code == AWS_ERROR_SUCCESS) {
+        /* Fallback code for if the error source was outside the CRT native implementation */
         error_code = AWS_ERROR_HTTP_CALLBACK_FAILURE;
     }
 
diff --git a/source/mqtt_client_connection.c b/source/mqtt_client_connection.c
index 70da32835..9eb73a950 100644
--- a/source/mqtt_client_connection.c
+++ b/source/mqtt_client_connection.c
@@ -615,13 +615,13 @@ PyObject *aws_py_mqtt_ws_handshake_transform_complete(PyObject *self, PyObject *
 
     PyObject *exception_py;
     PyObject *ws_transform_capsule;
-    if (!PyArg_ParseTuple(args, "OO", &exception_py, &ws_transform_capsule)) {
+    int error_code = AWS_ERROR_SUCCESS;
+    if (!PyArg_ParseTuple(args, "OOi", &exception_py, &ws_transform_capsule, &error_code)) {
         return NULL;
     }
 
-    int error_code = AWS_ERROR_SUCCESS;
-    if (exception_py != Py_None) {
-        /* TODO: Translate Python exception to aws error. In the meantime here's a catch-all. */
+    if (exception_py != Py_None && error_code == AWS_ERROR_SUCCESS) {
+        /* Fallback code for if the error source was outside the CRT native implementation */
         error_code = AWS_ERROR_HTTP_CALLBACK_FAILURE;
     }