diff --git a/etc/NEWS b/etc/NEWS
index b097757dab6d49288ce9c3c5b69032f5dd4caeff..68744dc9ff50b1fc5f553a096fee03872cfb47fb 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -60,10 +60,11 @@ name, group names known to the system (where possible).
 ** ImageMagick support, if available, is automatically enabled.
 It is no longer necessary to call `imagemagick-register-types'
 explicitly to install ImageMagick image types; that function is called
-automatically when setting `imagemagick-types-inhibit'.
+automatically at startup or when customizing `imagemagick-types-inhibit'.
 
 *** Setting `imagemagick-types-inhibit' to t now disables the use of
-ImageMagick to view images, set
+ImageMagick to view images.  You must call imagemagick-register-types
+afterwards if you do not use customize to change this.
 
 ** String values for `initial-buffer-choice' also apply to emacsclient
 frames, if emacsclient is only told to open a new frame without
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b3461821f8044143f85c1c3dcedbff03f1868ee2..36d81234a78ac7a1458482c1bc1f57baa6cb1d99 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,7 @@
 2012-05-25  Glenn Morris  <rgm@gnu.org>
 
+	* image.el (imagemagick-types-inhibit): Doc fix.
+
 	* version.el: Remove no-byte-compile and associated formatting.
 	* loadup.el: No need to load version.el uncompiled.  AFAICS, this
 	is ancient code from when there was an "inc-vers.el".
diff --git a/lisp/image.el b/lisp/image.el
index 27e41a57efec308a3e6e2b156b2006da6747a415..087cd148dd6650c06bf50f3bfbafd6ae91036a0c 100644
--- a/lisp/image.el
+++ b/lisp/image.el
@@ -735,6 +735,9 @@ image types are not registered by `imagemagick-register-types'.
 
 If the value is t, inhibit the use of ImageMagick for images.
 
+If you change this without using customize, you must call
+`imagemagick-register-types' afterwards.
+
 If Emacs is compiled without ImageMagick support, this variable
 has no effect."
   :type '(choice (const :tag "Support all ImageMagick types" nil)