diff --git a/httpbin/structures.py b/httpbin/structures.py
new file mode 100644
index 0000000..996b159
--- /dev/null
+++ b/httpbin/structures.py
@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+
+"""
+httpbin.structures
+~~~~~~~~~~~~~~~~~~~
+
+Data structures that power httpbin.
+"""
+
+
+class CaseInsensitiveDict(dict):
+    """Case-insensitive Dictionary for headers.
+
+    For example, ``headers['content-encoding']`` will return the
+    value of a ``'Content-Encoding'`` response header.
+    """
+
+    def _lower_keys(self):
+        return map(str.lower, self.keys())
+
+
+    def __contains__(self, key):
+        return key.lower() in self._lower_keys()
+
+
+    def __getitem__(self, key):
+        # We allow fall-through here, so values default to None
+        if key in self:
+            return self.items()[self._lower_keys().index(key.lower())][1]
\ No newline at end of file