diff --git a/tools/tinytest-codegen.py b/tools/tinytest-codegen.py
index 271eb55a3351a0d5a28b3c9d7b487d29e0d1689f..c4198832a7a5171bb4947d6ca80ab33cd221cd19 100755
--- a/tools/tinytest-codegen.py
+++ b/tools/tinytest-codegen.py
@@ -49,7 +49,7 @@ testgroup_member = (
 test_dirs = ('basics', 'micropython', 'extmod', 'inlineasm') # 'float', 'import', 'io', 'misc')
 exclude_tests = (
     'inlineasm/asmfpaddsub.py', 'inlineasm/asmfpcmp.py', 'inlineasm/asmfpldrstr.py', 'inlineasm/asmfpmuldiv.py', 'inlineasm/asmfpsqrt.py',
-    'extmod/time_ms_us.py',
+    'extmod/ticks_diff.py', 'extmod/time_ms_us.py',
     'extmod/ujson_dumps_float.py', 'extmod/ujson_loads_float.py',
     'extmod/uctypes_native_float.py', 'extmod/uctypes_le_float.py',
     'extmod/machine_pinbase.py', 'extmod/machine_pulse.py',