diff -r 1469c4fde8cd Doc/library/imghdr.rst
--- a/Doc/library/imghdr.rst	Sat Jan 18 18:31:41 2014 +0200
+++ b/Doc/library/imghdr.rst	Sun Jan 19 21:13:35 2014 +0100
@@ -48,6 +48,11 @@
 +------------+-----------------------------------+
 | ``'png'``  | Portable Network Graphics         |
 +------------+-----------------------------------+
+| ``'exr'``  | OpenEXR Files                     |
++------------+-----------------------------------+
+
+.. versionadded:: 3.5
+   The *exr* format was added.
 
 You can extend the list of file types :mod:`imghdr` can recognize by appending
 to this variable:
diff -r 1469c4fde8cd Lib/imghdr.py
--- a/Lib/imghdr.py	Sat Jan 18 18:31:41 2014 +0200
+++ b/Lib/imghdr.py	Sun Jan 19 21:13:35 2014 +0100
@@ -112,6 +112,12 @@
 
 tests.append(test_bmp)
 
+def test_exr(h, f):
+    if h.startswith(b'\x76\x2f\x31\x01'):
+        return 'exr'
+
+tests.append(test_exr)
+
 #--------------------#
 # Small test program #
 #--------------------#