diff --git a/tools/gen-cpydiff.py b/tools/gen-cpydiff.py
index c9f58ec505..1d458d3dcd 100644
--- a/tools/gen-cpydiff.py
+++ b/tools/gen-cpydiff.py
@@ -50,7 +50,6 @@ INDEXTEMPLATE = "../docs/differences/index_template.txt"
 INDEX = "index.rst"
 
 HEADER = ".. This document was generated by tools/gen-cpydiff.py\n\n"
-UIMPORTLIST = {"struct", "collections", "json"}
 CLASSMAP = {"Core": "Core language", "Types": "Builtin types"}
 INDEXPRIORITY = ["syntax", "core_language", "builtin_types", "modules"]
 RSTCHARS = ["=", "-", "~", "`", ":"]
@@ -94,21 +93,12 @@ def readfiles():
     return files
 
 
-def uimports(code):
-    """converts CPython module names into MicroPython equivalents"""
-    for uimport in UIMPORTLIST:
-        uimport = bytes(uimport, "utf8")
-        code = code.replace(uimport, b"u" + uimport)
-    return code
-
-
 def run_tests(tests):
     """executes all tests"""
     results = []
     for test in tests:
         with open(TESTPATH + test.name, "rb") as f:
-            input_cpy = f.read()
-        input_upy = uimports(input_cpy)
+            input_py = f.read()
 
         process = subprocess.Popen(
             CPYTHON3,
@@ -117,7 +107,7 @@ def run_tests(tests):
             stdin=subprocess.PIPE,
             stderr=subprocess.PIPE,
         )
-        output_cpy = [com.decode("utf8") for com in process.communicate(input_cpy)]
+        output_cpy = [com.decode("utf8") for com in process.communicate(input_py)]
 
         process = subprocess.Popen(
             MICROPYTHON,
@@ -126,7 +116,7 @@ def run_tests(tests):
             stdin=subprocess.PIPE,
             stderr=subprocess.PIPE,
         )
-        output_upy = [com.decode("utf8") for com in process.communicate(input_upy)]
+        output_upy = [com.decode("utf8") for com in process.communicate(input_py)]
 
         if output_cpy[0] == output_upy[0] and output_cpy[1] == output_upy[1]:
             status = "Supported"