diff --git a/python/convert.c b/python/convert.c
index b9df501..b079bdc 100644
--- a/python/convert.c
+++ b/python/convert.c
@@ -30,7 +30,7 @@
 #include "python/message.h"
 #include "python/protobuf.h"
 #include "upb/map.h"
-#include "upb/reflection.h"
+#include "upb/reflection/message.h"
 #include "upb/util/compare.h"
 
 // Must be last.
diff --git a/python/convert.h b/python/convert.h
index d26aeb7..c02c197 100644
--- a/python/convert.h
+++ b/python/convert.h
@@ -29,8 +29,8 @@
 #define PYUPB_CONVERT_H__
 
 #include "protobuf.h"
-#include "upb/def.h"
-#include "upb/reflection.h"
+#include "upb/reflection/def.h"
+#include "upb/reflection/message.h"
 
 // Converts `val` to a Python object according to the type information in `f`.
 // Any newly-created Python objects that reference non-primitive data from `val`
diff --git a/python/descriptor.c b/python/descriptor.c
index 4d238bc..5e3a5fd 100644
--- a/python/descriptor.c
+++ b/python/descriptor.c
@@ -32,7 +32,7 @@
 #include "python/descriptor_pool.h"
 #include "python/message.h"
 #include "python/protobuf.h"
-#include "upb/def.h"
+#include "upb/reflection/def.h"
 #include "upb/util/def_to_proto.h"
 
 // -----------------------------------------------------------------------------
diff --git a/python/descriptor.h b/python/descriptor.h
index b4229ef..9bf6b42 100644
--- a/python/descriptor.h
+++ b/python/descriptor.h
@@ -31,7 +31,7 @@
 #include <stdbool.h>
 
 #include "python/python_api.h"
-#include "upb/def.h"
+#include "upb/reflection/def.h"
 
 typedef enum {
   kPyUpb_Descriptor = 0,
diff --git a/python/descriptor_containers.c b/python/descriptor_containers.c
index 0f2d4ff..c750a4a 100644
--- a/python/descriptor_containers.c
+++ b/python/descriptor_containers.c
@@ -29,7 +29,7 @@
 
 #include "python/descriptor.h"
 #include "python/protobuf.h"
-#include "upb/def.h"
+#include "upb/reflection/def.h"
 
 // Implements __repr__ as str(dict(self)).
 static PyObject* PyUpb_DescriptorMap_Repr(PyObject* _self) {
diff --git a/python/descriptor_containers.h b/python/descriptor_containers.h
index 8c6b0d9..276aea5 100644
--- a/python/descriptor_containers.h
+++ b/python/descriptor_containers.h
@@ -43,7 +43,7 @@
 #include <stdbool.h>
 
 #include "protobuf.h"
-#include "upb/def.h"
+#include "upb/reflection/def.h"
 
 // -----------------------------------------------------------------------------
 // PyUpb_GenericSequence
diff --git a/python/descriptor_pool.c b/python/descriptor_pool.c
index ea0e813..4e9faaa 100644
--- a/python/descriptor_pool.c
+++ b/python/descriptor_pool.c
@@ -32,7 +32,7 @@
 #include "python/descriptor.h"
 #include "python/message.h"
 #include "python/protobuf.h"
-#include "upb/def.h"
+#include "upb/reflection/def.h"
 #include "upb/util/def_to_proto.h"
 
 // -----------------------------------------------------------------------------
diff --git a/python/map.c b/python/map.c
index c5c6e68..dfadf41 100644
--- a/python/map.c
+++ b/python/map.c
@@ -30,8 +30,8 @@
 #include "python/convert.h"
 #include "python/message.h"
 #include "python/protobuf.h"
-#include "upb/def.h"
 #include "upb/map.h"
+#include "upb/reflection/def.h"
 
 // -----------------------------------------------------------------------------
 // MapContainer
diff --git a/python/map.h b/python/map.h
index aaa4e20..e69ff9f 100644
--- a/python/map.h
+++ b/python/map.h
@@ -31,7 +31,7 @@
 #include <stdbool.h>
 
 #include "python/python_api.h"
-#include "upb/def.h"
+#include "upb/reflection/def.h"
 
 // Creates a new repeated field stub for field `f` of message object `parent`.
 // Precondition: `parent` must be a stub.
diff --git a/python/message.c b/python/message.c
index e67bf23..1752922 100644
--- a/python/message.c
+++ b/python/message.c
@@ -32,8 +32,8 @@
 #include "python/extension_dict.h"
 #include "python/map.h"
 #include "python/repeated.h"
-#include "upb/def.h"
-#include "upb/reflection.h"
+#include "upb/reflection/def.h"
+#include "upb/reflection/message.h"
 #include "upb/text_encode.h"
 #include "upb/util/required_fields.h"
 
diff --git a/python/message.h b/python/message.h
index f296d5c..f10f15f 100644
--- a/python/message.h
+++ b/python/message.h
@@ -31,7 +31,7 @@
 #include <stdbool.h>
 
 #include "python/protobuf.h"
-#include "upb/reflection.h"
+#include "upb/reflection/message.h"
 
 // Removes the wrapper object for this field from the unset subobject cache.
 void PyUpb_Message_CacheDelete(PyObject* _self, const upb_FieldDef* f);
diff --git a/python/repeated.h b/python/repeated.h
index 5d74bd2..8cd3872 100644
--- a/python/repeated.h
+++ b/python/repeated.h
@@ -31,7 +31,7 @@
 #include <stdbool.h>
 
 #include "python/python_api.h"
-#include "upb/def.h"
+#include "upb/reflection/def.h"
 
 // Creates a new repeated field stub for field `f` of message object `parent`.
 // Precondition: `parent` must be a stub.