diff -r ec81edc30221 Tools/freeze/bkfile.py
--- a/Tools/freeze/bkfile.py	Sat Nov 08 22:41:00 2014 +0200
+++ b/Tools/freeze/bkfile.py	Sun Nov 09 15:42:46 2014 +0200
@@ -33,6 +33,12 @@ class _BkFile:
         self.write = self.__file.write
         self.writelines = self.__file.writelines
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
     def close(self):
         self.__file.close()
         if self.__backup is None:
diff -r ec81edc30221 Tools/freeze/freeze.py
--- a/Tools/freeze/freeze.py	Sat Nov 08 22:41:00 2014 +0200
+++ b/Tools/freeze/freeze.py	Sun Nov 09 15:42:46 2014 +0200
@@ -451,13 +451,9 @@ def main():
 
     # generate config.c and Makefile
     builtins.sort()
-    infp = open(config_c_in)
-    outfp = bkfile.open(config_c, 'w')
-    try:
+    with open(config_c_in) as infp, \
+         bkfile.open(config_c, 'w') as outfp:
         makeconfig.makeconfig(infp, outfp, builtins)
-    finally:
-        outfp.close()
-    infp.close()
 
     cflags = ['$(OPT)']
     cppflags = defines + includes
@@ -475,11 +471,8 @@ def main():
             files + supp_sources +  addfiles + libs + \
             ['$(MODLIBS)', '$(LIBS)', '$(SYSLIBS)']
 
-    outfp = bkfile.open(makefile, 'w')
-    try:
+    with bkfile.open(makefile, 'w') as outfp:
         makemakefile.makemakefile(outfp, somevars, files, base_target)
-    finally:
-        outfp.close()
 
     # Done!
 
diff -r ec81edc30221 Tools/freeze/makefreeze.py
--- a/Tools/freeze/makefreeze.py	Sat Nov 08 22:41:00 2014 +0200
+++ b/Tools/freeze/makefreeze.py	Sun Nov 09 15:42:46 2014 +0200
@@ -39,36 +39,34 @@ def makefreeze(base, dict, debug=0, entr
         mangled = "__".join(mod.split("."))
         if m.__code__:
             file = 'M_' + mangled + '.c'
-            outfp = bkfile.open(base + file, 'w')
-            files.append(file)
-            if debug:
-                print("freezing", mod, "...")
-            str = marshal.dumps(m.__code__)
-            size = len(str)
-            if m.__path__:
-                # Indicate package by negative size
-                size = -size
-            done.append((mod, mangled, size))
-            writecode(outfp, mangled, str)
-            outfp.close()
+            with bkfile.open(base + file, 'w') as outfp:
+                files.append(file)
+                if debug:
+                    print("freezing", mod, "...")
+                str = marshal.dumps(m.__code__)
+                size = len(str)
+                if m.__path__:
+                    # Indicate package by negative size
+                    size = -size
+                done.append((mod, mangled, size))
+                writecode(outfp, mangled, str)
     if debug:
         print("generating table of frozen modules")
-    outfp = bkfile.open(base + 'frozen.c', 'w')
-    for mod, mangled, size in done:
-        outfp.write('extern unsigned char M_%s[];\n' % mangled)
-    outfp.write(header)
-    for mod, mangled, size in done:
-        outfp.write('\t{"%s", M_%s, %d},\n' % (mod, mangled, size))
-    outfp.write('\n')
-    # The following modules have a NULL code pointer, indicating
-    # that the frozen program should not search for them on the host
-    # system. Importing them will *always* raise an ImportError.
-    # The zero value size is never used.
-    for mod in fail_import:
-        outfp.write('\t{"%s", NULL, 0},\n' % (mod,))
-    outfp.write(trailer)
-    outfp.write(entry_point)
-    outfp.close()
+    with bkfile.open(base + 'frozen.c', 'w') as outfp:
+        for mod, mangled, size in done:
+            outfp.write('extern unsigned char M_%s[];\n' % mangled)
+        outfp.write(header)
+        for mod, mangled, size in done:
+            outfp.write('\t{"%s", M_%s, %d},\n' % (mod, mangled, size))
+        outfp.write('\n')
+        # The following modules have a NULL code pointer, indicating
+        # that the frozen program should not search for them on the host
+        # system. Importing them will *always* raise an ImportError.
+        # The zero value size is never used.
+        for mod in fail_import:
+            outfp.write('\t{"%s", NULL, 0},\n' % (mod,))
+        outfp.write(trailer)
+        outfp.write(entry_point)
     return files