diff --git a/Modules/errnomodule.c b/Modules/errnomodule.c
index 8120075..f18a655 100644
--- a/Modules/errnomodule.c
+++ b/Modules/errnomodule.c
@@ -94,7 +94,7 @@
 To map error codes to error messages, use the function os.strerror(),\n\
 e.g. os.strerror(2) could return 'No such file or directory'.";
 
-void
+DL_EXPORT(void)
 initerrno()
 {
 	PyObject *m, *d, *de;