diff --git a/lib/redcloth3.rb b/lib/redcloth3.rb
index e0dca80e..a4d33f80 100644
--- a/lib/redcloth3.rb
+++ b/lib/redcloth3.rb
@@ -907,7 +907,7 @@ class RedCloth3 < String
     end
 
     IMAGE_RE = /
-            (<p>|.|^)            # start of line?
+            (<p>|\s|^)           # start of line?
             \!                   # opening
             (\<|\=|\>)?          # optional alignment atts
             (#{C})               # optional style,class atts
diff --git a/test/unit/helpers/application_helper_test.rb b/test/unit/helpers/application_helper_test.rb
index a8b7edea..21ed10ae 100644
--- a/test/unit/helpers/application_helper_test.rb
+++ b/test/unit/helpers/application_helper_test.rb
@@ -57,6 +57,8 @@ class ApplicationHelperTest < HelperTestCase
       'ftp://foo.bar' => '<a class="external" href="ftp://foo.bar">ftp://foo.bar</a>',
       'ftps://foo.bar' => '<a class="external" href="ftps://foo.bar">ftps://foo.bar</a>',
       'sftp://foo.bar' => '<a class="external" href="sftp://foo.bar">sftp://foo.bar</a>',
+      # two exclamation marks
+      'http://example.net/path!602815048C7B5C20!302.html' => '<a class="external" href="http://example.net/path!602815048C7B5C20!302.html">http://example.net/path!602815048C7B5C20!302.html</a>',
     }
     to_test.each { |text, result| assert_equal "<p>#{result}</p>", textilizable(text) }
   end
@@ -110,6 +112,8 @@ class ApplicationHelperTest < HelperTestCase
       "This is a double quote \"on the first line\nand another on a second line\":test" => "This is a double quote \"on the first line<br />\nand another on a second line\":test",
       # mailto link
       "\"system administrator\":mailto:sysadmin@example.com?subject=redmine%20permissions" => "<a href=\"mailto:sysadmin@example.com?subject=redmine%20permissions\">system administrator</a>",
+      # two exclamation marks
+      '"a link":http://example.net/path!602815048C7B5C20!302.html' => '<a href="http://example.net/path!602815048C7B5C20!302.html" class="external">a link</a>',
     }
     to_test.each { |text, result| assert_equal "<p>#{result}</p>", textilizable(text) }
   end