diff --git a/src/SConstruct b/src/SConstruct
index a95c803..6fe5cc1 100644
--- a/src/SConstruct
+++ b/src/SConstruct
@@ -1,9 +1,6 @@
-from sysconfig import get_config_var
 import os
 
 ###############################################################################
-suffix = get_config_var('EXT_SUFFIX')
-
 def filtered_glob(env, pattern, omit=[],
   ondisk=True, source=False, strings=False):
     return list(filter(
@@ -12,27 +9,26 @@ def filtered_glob(env, pattern, omit=[],
 
 # Create a builder for f2py
 def f2py_generator(source, target, env, for_signature):
+    suffix = ".so"
     main = source[0]
     objects = " ".join(o.get_path() for o in source[1:] if str(o).endswith('.o'))
-    modulename = str(target[0]).replace(suffix, '').replace('/', '.')
+    moduledir  = os.path.dirname(target[0].abspath)
+    modulefile = str(target[0])
+    modulename = modulefile.replace(suffix, '').replace('/', '.')
     compiler = env['FORTRAN']
     cmd  = f"f2py3 --fcompiler={compiler} "
     cmd += f" $F2PY_OPTS -m {modulename} -c {objects} {main}"
+    cmd += f" && cp {'/'.join(modulename.split('.'))}.*.so {modulefile}"
     #cmd += " 1>/dev/null 2>/dev/null"
     return cmd
 
-def f2py_emitter(target, source, env):
-    """ used to add the correct cpython .so suffix to the modulename """
-    target[0] = str(target[0]).replace('.', '/') + suffix
-    return target, source
-
 def install_module(env, module):
     destdir = os.path.dirname(module[0].srcnode().abspath)
     env.Install(destdir, module)
     env.Alias('install', destdir)
     return None
 
-f2py_bld = Builder(generator=f2py_generator, emitter=f2py_emitter)
+f2py_bld = Builder(generator=f2py_generator)
 
 # define the default build environment
 std  = Environment(tools=['default', 'fortran'], F2PY_OPTS=[], LIBS=[])
diff --git a/src/msspec/phagen/fortran/SConstruct b/src/msspec/phagen/fortran/SConstruct
index c83bfdd..3716a3d 100644
--- a/src/msspec/phagen/fortran/SConstruct
+++ b/src/msspec/phagen/fortran/SConstruct
@@ -4,7 +4,7 @@ import os
 objects_src= ['phagen_scf_2.1_dp.f']
 objects = env.Object(objects_src)
 
-module = env.F2py('libphagen', ['main.f'] + objects, F2PYCOMSTR=">>")
+module = env.F2py('libphagen.so', ['main.f'] + objects, F2PYCOMSTR=">>")
 env.InstallModule(module)
 
 env.Alias('phagen', module)
diff --git a/src/msspec/spec/fortran/SConstruct b/src/msspec/spec/fortran/SConstruct
index 3fd43b2..18ef38c 100644
--- a/src/msspec/spec/fortran/SConstruct
+++ b/src/msspec/spec/fortran/SConstruct
@@ -45,19 +45,19 @@ Requires(memalloc_obj, dim_mod_obj)
 common_deps = dim_mod_obj + memalloc_obj + cluster_gen_obj + common_sub_obj
 
 deps = common_deps + renormalization_obj + phd_se_noso_nosp_nosym_obj
-phd_se_mod = env_spec.F2py('_phd_se_noso_nosp_nosym', ['phd_se_noso_nosp_nosym/main.f'] + deps)
+phd_se_mod = env_spec.F2py('_phd_se_noso_nosp_nosym.so', ['phd_se_noso_nosp_nosym/main.f'] + deps)
 env_spec.InstallModule(phd_se_mod)
 
 deps = common_deps + renormalization_obj + phd_mi_noso_nosp_nosym_obj
-phd_mi_mod = env_spec.F2py('_phd_mi_noso_nosp_nosym', ['phd_mi_noso_nosp_nosym/main.f'] + deps)
+phd_mi_mod = env_spec.F2py('_phd_mi_noso_nosp_nosym.so', ['phd_mi_noso_nosp_nosym/main.f'] + deps)
 env_spec.InstallModule(phd_mi_mod)
 
 deps = common_deps + renormalization_obj + eig_common_obj + eig_mi_obj
-eig_mi_mod = env_spec.F2py('_eig_mi', ['eig/mi/main.f'] + deps)
+eig_mi_mod = env_spec.F2py('_eig_mi.so', ['eig/mi/main.f'] + deps)
 env_spec.InstallModule(eig_mi_mod)
 
 deps = common_deps + renormalization_obj + eig_common_obj + eig_pw_obj
-eig_pw_mod = env_spec.F2py('_eig_pw', ['eig/pw/main.f'] + deps)
+eig_pw_mod = env_spec.F2py('_eig_pw.so', ['eig/pw/main.f'] + deps)
 env_spec.InstallModule(eig_pw_mod)
 
 # Alias