diff --git a/klippy/chelper/__init__.py b/klippy/chelper/__init__.py
index 851fda70..76d5c4b4 100644
--- a/klippy/chelper/__init__.py
+++ b/klippy/chelper/__init__.py
@@ -218,6 +218,10 @@ FFI_main = None
 FFI_lib = None
 pyhelper_logging_callback = None
 
+# Hepler invoked from C errorf() code to log errors
+def logging_callback(msg):
+    logging.error(FFI_main.string(msg))
+
 # Return the Foreign Function Interface api to the caller
 def get_ffi():
     global FFI_main, FFI_lib, pyhelper_logging_callback
@@ -238,10 +242,8 @@ def get_ffi():
             FFI_main.cdef(d)
         FFI_lib = FFI_main.dlopen(destlib)
         # Setup error logging
-        def logging_callback(msg):
-            logging.error(FFI_main.string(msg))
-        pyhelper_logging_callback = FFI_main.callback(
-            "void func(const char *)", logging_callback)
+        pyhelper_logging_callback = FFI_main.callback("void func(const char *)",
+                                                      logging_callback)
         FFI_lib.set_python_logging_callback(pyhelper_logging_callback)
     return FFI_main, FFI_lib