diff --git a/py_aax_decode/native.py b/py_aax_decode/native.py
index 93b3ce8..ed0196e 100644
--- a/py_aax_decode/native.py
+++ b/py_aax_decode/native.py
@@ -83,7 +83,7 @@ def get_audio_channel_count(dll, handle):
 
 def get_sample_rate(dll, handle):
     sample_rate = ctypes.c_uint()
-    res = dll.AAXGetSampleRate(handle, n_channels)
+    res = dll.AAXGetSampleRate(handle, sample_rate)
 
     if res != 0:
         raise Exception('AAXGetSampleRate: {}'.format(res))