diff --git a/setup.py b/setup.py
index a1617f9f74bcd0e249c1a937704a4c48b7c9f3a5..7ece3f95c2eeec0f39020a7e2dcab2f252f6d5df 100644
--- a/setup.py
+++ b/setup.py
@@ -59,12 +59,13 @@ def has_flag(compiler, flagname):
     the specified compiler.
     """
     import tempfile
-    with tempfile.NamedTemporaryFile('w', suffix='.cpp') as f:
+    with tempfile.NamedTemporaryFile('w', suffix='.cpp', delete=False) as f:
         f.write('int main (int argc, char **argv) { return 0; }')
-        try:
-            compiler.compile([f.name], extra_postargs=[flagname])
-        except setuptools.distutils.errors.CompileError:
-            return False
+        fname = f.name
+    try:
+        compiler.compile([fname], extra_postargs=[flagname])
+    except setuptools.distutils.errors.CompileError:
+        return False
     return True
 
 
@@ -95,7 +96,7 @@ class BuildExt(build_ext):
     def build_extensions(self):
         ct = self.compiler.compiler_type
         opts = self.c_opts.get(ct, [])
-        if ct == 'unix':
+        if ct in ['unix', 'mingw32']:
             opts.append('-DVERSION_INFO="%s"' % self.distribution.get_version())
             opts.append(cpp_flag(self.compiler))
             if has_flag(self.compiler, '-fvisibility=hidden'):