diff --git a/setup.py b/setup.py
index f98cc3cc..625341d4 100644
--- a/setup.py
+++ b/setup.py
@@ -16,20 +16,19 @@
 """
 
 if os.name == "nt":
-    link_args = ['/EXPORT:calc_model_1', '/EXPORT:calc_model_2']
+    core1_ext = Extension('xija.core_1', ['xija/core_1.c'],
+                      extra_link_args=['/EXPORT:calc_model_1'])
+    core2_ext = Extension('xija.core_2', ['xija/core_2.c'],
+                      extra_link_args=['/EXPORT:calc_model_2'])
 else:
-    link_args = []
+    core1_ext = Extension('xija.core_1', ['xija/core_1.c'])
+    core2_ext = Extension('xija.core_2', ['xija/core_2.c'])
 
 try:
     from testr.setup_helper import cmdclass
 except ImportError:
     cmdclass = {}
 
-core1_ext = Extension('xija.core_1', ['xija/core_1.c'],
-                      extra_link_args=link_args)
-core2_ext = Extension('xija.core_2', ['xija/core_2.c'],
-                      extra_link_args=link_args)
-
 entry_points = {'console_scripts': 'xija_gui_fit = xija.gui_fit:main'}
 
 setup(name='xija',
diff --git a/xija/core_1.c b/xija/core_1.c
index 03538800..42c2bd79 100644
--- a/xija/core_1.c
+++ b/xija/core_1.c
@@ -5,7 +5,7 @@
 #if PY_MAJOR_VERSION < 3
 void initcore(void)
 #else
-void PyInit_core(void)
+void PyInit_core_1(void)
 #endif
 {
     /* stub initialization function needed by distutils on Windows */
diff --git a/xija/core_2.c b/xija/core_2.c
index 927bdc07..3c0ed22b 100644
--- a/xija/core_2.c
+++ b/xija/core_2.c
@@ -5,7 +5,7 @@
 #if PY_MAJOR_VERSION < 3
 void initcore(void)
 #else
-void PyInit_core(void)
+void PyInit_core_2(void)
 #endif
 {
     /* stub initialization function needed by distutils on Windows */