diff --git a/av/dictionary.pxd b/av/dictionary.pxd
index 1c59df448..47c100adc 100644
--- a/av/dictionary.pxd
+++ b/av/dictionary.pxd
@@ -2,9 +2,7 @@ cimport libav as lib
 
 
 cdef class _Dictionary:
-
     cdef lib.AVDictionary *ptr
-
     cpdef _Dictionary copy(self)
 
 
diff --git a/av/dictionary.py b/av/dictionary.py
new file mode 100644
index 000000000..2080266ed
--- /dev/null
+++ b/av/dictionary.py
@@ -0,0 +1,62 @@
+from collections.abc import MutableMapping
+
+import cython
+from cython.cimports.av.error import err_check
+
+
+@cython.cclass
+class _Dictionary:
+    def __cinit__(self, *args, **kwargs):
+        for arg in args:
+            self.update(arg)
+        if kwargs:
+            self.update(kwargs)
+
+    def __dealloc__(self):
+        if self.ptr != cython.NULL:
+            lib.av_dict_free(cython.address(self.ptr))
+
+    def __getitem__(self, key: cython.str):
+        element = cython.declare(
+            cython.pointer[lib.AVDictionaryEntry],
+            lib.av_dict_get(self.ptr, key, cython.NULL, 0),
+        )
+        if element == cython.NULL:
+            raise KeyError(key)
+        return element.value
+
+    def __setitem__(self, key: cython.str, value: cython.str):
+        err_check(lib.av_dict_set(cython.address(self.ptr), key, value, 0))
+
+    def __delitem__(self, key: cython.str):
+        err_check(lib.av_dict_set(cython.address(self.ptr), key, cython.NULL, 0))
+
+    def __len__(self):
+        return err_check(lib.av_dict_count(self.ptr))
+
+    def __iter__(self):
+        element = cython.declare(cython.pointer[lib.AVDictionaryEntry], cython.NULL)
+        while True:
+            element = lib.av_dict_get(self.ptr, "", element, lib.AV_DICT_IGNORE_SUFFIX)
+            if element == cython.NULL:
+                break
+            yield element.key
+
+    def __repr__(self):
+        return f"bv.Dictionary({dict(self)!r})"
+
+    def copy(self):
+        other = cython.declare(_Dictionary, Dictionary())
+        lib.av_dict_copy(cython.address(other.ptr), self.ptr, 0)
+        return other
+
+
+class Dictionary(_Dictionary, MutableMapping):
+    pass
+
+
+@cython.cfunc
+def wrap_dictionary(input_: cython.pointer[lib.AVDictionary]) -> _Dictionary:
+    output = cython.declare(_Dictionary, Dictionary())
+    output.ptr = input_
+    return output
diff --git a/av/dictionary.pyx b/av/dictionary.pyx
deleted file mode 100644
index 15de38381..000000000
--- a/av/dictionary.pyx
+++ /dev/null
@@ -1,57 +0,0 @@
-from collections.abc import MutableMapping
-
-from av.error cimport err_check
-
-
-cdef class _Dictionary:
-    def __cinit__(self, *args, **kwargs):
-        for arg in args:
-            self.update(arg)
-        if kwargs:
-            self.update(kwargs)
-
-    def __dealloc__(self):
-        if self.ptr != NULL:
-            lib.av_dict_free(&self.ptr)
-
-    def __getitem__(self, str key):
-        cdef lib.AVDictionaryEntry *element = lib.av_dict_get(self.ptr, key, NULL, 0)
-        if element != NULL:
-            return element.value
-        else:
-            raise KeyError(key)
-
-    def __setitem__(self, str key, str value):
-        err_check(lib.av_dict_set(&self.ptr, key, value, 0))
-
-    def __delitem__(self, str key):
-        err_check(lib.av_dict_set(&self.ptr, key, NULL, 0))
-
-    def __len__(self):
-        return err_check(lib.av_dict_count(self.ptr))
-
-    def __iter__(self):
-        cdef lib.AVDictionaryEntry *element = NULL
-        while True:
-            element = lib.av_dict_get(self.ptr, "", element, lib.AV_DICT_IGNORE_SUFFIX)
-            if element == NULL:
-                break
-            yield element.key
-
-    def __repr__(self):
-        return f"av.Dictionary({dict(self)!r})"
-
-    cpdef _Dictionary copy(self):
-        cdef _Dictionary other = Dictionary()
-        lib.av_dict_copy(&other.ptr, self.ptr, 0)
-        return other
-
-
-class Dictionary(_Dictionary, MutableMapping):
-    pass
-
-
-cdef _Dictionary wrap_dictionary(lib.AVDictionary *input_):
-    cdef _Dictionary output = Dictionary()
-    output.ptr = input_
-    return output
diff --git a/av/plane.pxd b/av/plane.pxd
index df3847d7b..2066bfea8 100644
--- a/av/plane.pxd
+++ b/av/plane.pxd
@@ -3,9 +3,7 @@ from av.frame cimport Frame
 
 
 cdef class Plane(Buffer):
-
     cdef Frame frame
     cdef int index
-
     cdef size_t _buffer_size(self)
     cdef void* _buffer_ptr(self)
diff --git a/av/plane.pyx b/av/plane.py
similarity index 72%
rename from av/plane.pyx
rename to av/plane.py
index c733b20a7..f84a99c3d 100644
--- a/av/plane.pyx
+++ b/av/plane.py
@@ -1,12 +1,15 @@
+import cython
 
-cdef class Plane(Buffer):
+
+@cython.cclass
+class Plane(Buffer):
     """
     Base class for audio and video planes.
 
     See also :class:`~av.audio.plane.AudioPlane` and :class:`~av.video.plane.VideoPlane`.
     """
 
-    def __cinit__(self, Frame frame, int index):
+    def __cinit__(self, frame: Frame, index: cython.int):
         self.frame = frame
         self.index = index
 
@@ -16,5 +19,6 @@ def __repr__(self):
             f"buffer_ptr=0x{self.buffer_ptr:x}; at 0x{id(self):x}>"
         )
 
-    cdef void* _buffer_ptr(self):
+    @cython.cfunc
+    def _buffer_ptr(self) -> cython.p_void:
         return self.frame.ptr.extended_data[self.index]