diff --git a/util/htmlminimizer.py b/util/htmlminimizer.py
index ab6e1e3..6539757 100755
--- a/util/htmlminimizer.py
+++ b/util/htmlminimizer.py
@@ -13,39 +13,39 @@ available_server = itertools.cycle(_SERVERS)
 input_file = sys.argv[1]
 output_file = sys.argv[2]
 in_pre = False
-out = open(output_file, 'w', encoding="utf-8") # encoding argument! important!
-for line in open(input_file, encoding="utf-8").readlines():
-    # round-robin image servers
-    if "<img src=i/" in line:
-        line = line.replace("<img src=i/", "<img src=http://" + next(available_server) + "/dip3/")
-    if "url(i/" in line:
-        line = line.replace("url(i/", "url(http://" + next(available_server) + "/dip3/")
+with open(output_file, 'w', encoding="utf-8") as _out, open(input_file, encoding="utf-8") as _in:
+    for line in _in:
+        # round-robin image servers
+        if "<img src=i/" in line:
+            line = line.replace("<img src=i/", "<img src=http://" + next(available_server) + "/dip3/")
+        if "url(i/" in line:
+            line = line.replace("url(i/", "url(http://" + next(available_server) + "/dip3/")
 
-    # replace entities with Unicode characters
-    for e in re.findall('&(.+?);', line):
-        if e in ('lt', 'amp', 'quot', 'apos', 'nbsp'):
-            continue
-        n = html.entities.name2codepoint.get(e)
-        if not n:
-            if e.count('#x'):
-                # it's late, forgive me
-                n = eval(e.replace('#', '0'))
-            elif e.count('#'):
-                n = int(e.replace('#', ''))
-            else:
+        # replace entities with Unicode characters
+        for e in re.findall('&(.+?);', line):
+            if e in ('lt', 'amp', 'quot', 'apos', 'nbsp'):
                 continue
-        line = line.replace('&' + e + ';', chr(n))
-
-    # strip leading and trailing whitespace, except inside <pre> blocks
-    g = line.strip()
-    if g.count('<pre'):
-        in_pre = True
-    if g.count('</pre'):
-        # XXX this will break if you have </pre><pre> in one line
-        in_pre = False
-        g = line.rstrip()
-    if in_pre:
-        out.write(line)
-    else:
-        out.write(g)
-out.close()
+            n = html.entities.name2codepoint.get(e)
+            if not n:
+                if e.count('#x'):
+                    # it's late, forgive me
+                    n = eval(e.replace('#', '0'))
+                elif e.count('#'):
+                    n = int(e.replace('#', ''))
+                else:
+                    continue
+            line = line.replace('&' + e + ';', chr(n))
+    
+        # strip leading and trailing whitespace, except inside <pre> blocks
+        g = line.strip()
+        if g.count('<pre'):
+            in_pre = True
+        if g.count('</pre'):
+            # XXX this will break if you have </pre><pre> in one line
+            in_pre = False
+            g = line.rstrip()
+        if in_pre:
+            _out.write(line)
+        else:
+            _out.write(g)
+