Index: Modules/binascii.c
===================================================================
--- Modules/binascii.c	(revision 74244)
+++ Modules/binascii.c	(working copy)
@@ -420,10 +420,14 @@
 			}
 		}
 
+		/* Fail on non-base64-encoded character. */
 		this_ch = table_a2b_base64[*ascii_data];
-		if ( this_ch == (unsigned char) -1 )
-			continue;
-
+		if ( this_ch == (unsigned char) -1 ) {
+			PyErr_SetString(PyExc_TypeError, "Non-base64 digit found");
+			Py_DECREF(rv);
+			return NULL;
+		}
+		
 		/*
 		** Shift it in on the low end, and see if there's
 		** a byte ready for output.
Index: Lib/test/test_base64.py
===================================================================
--- Lib/test/test_base64.py	(revision 74244)
+++ Lib/test/test_base64.py	(working copy)
@@ -137,7 +137,18 @@
         self.assertRaises(TypeError, base64.urlsafe_b64decode, "")
 
     def test_b64decode_error(self):
-        self.assertRaises(binascii.Error, base64.b64decode, b'abc')
+        ar = self.assertRaises
+        ar(binascii.Error, base64.b64decode, b'abc')
+        # Test some invalid characters; addresses [1466065].
+        ar(TypeError, base64.b64decode, b'%3d3LnB5dGhvbi5vcmc=')
+        ar(TypeError, base64.b64decode, b'$3d3LnB5dGhvbi5vcmc=')
+        ar(TypeError, base64.b64decode, b'[3d3LnB5dGhvbi5vcmc=')
+        ar(TypeError, base64.b64decode, b']3d3LnB5dGhvbi5vcmc=')
+        ar(TypeError, base64.b64decode, b'{3d3LnB5dGhvbi5vcmc=')
+        ar(TypeError, base64.b64decode, b'}3d3LnB5dGhvbi5vcmc=')
+        ar(TypeError, base64.b64decode, b'@3d3LnB5dGhvbi5vcmc=')
+        ar(TypeError, base64.b64decode, b'!3d3LnB5dGhvbi5vcmc=')
+        ar(TypeError, base64.b64decode, b'#3d3LnB5dGhvbi5vcmc=')
 
     def test_b32encode(self):
         eq = self.assertEqual