--- ./numpy/f2py/tests/test_compile_function.py.orig    2020-06-04 16:12:09 +0200
+++ ./numpy/f2py/tests/test_compile_function.py 2020-06-04 16:12:58 +0200
@@ -85,6 +85,10 @@
             # Removal from sys.modules, is not as such necessary. Even with
             # removal, the module (dict) stays alive.
             del sys.modules[modname]
+            # On AIX, you cannot compile the .so if it was previously loaded.
+            # We must clean it before
+            if sys.platform == 'aix':
+                os.remove(os.path.join(moddir, modname + ".so"))
 
 
 def test_f2py_init_compile_failure():