diff --git a/theme/base/images/icons/icons-01.gif b/theme/base/images/icons/icons-01.gif
new file mode 100644
index 0000000000..f19d6a3f68
Binary files /dev/null and b/theme/base/images/icons/icons-01.gif differ
diff --git a/theme/base/images/icons/icons-01.png b/theme/base/images/icons/icons-01.png
deleted file mode 100644
index c0f087a214..0000000000
Binary files a/theme/base/images/icons/icons-01.png and /dev/null differ
diff --git a/theme/default/css/display.css b/theme/default/css/display.css
index 048b85fda1..87bd367e0d 100644
--- a/theme/default/css/display.css
+++ b/theme/default/css/display.css
@@ -137,7 +137,7 @@ button.close,
 .form_user_unsubscribe input.submit,
 .form_group_join input.submit,
 .form_user_subscribe input.submit {
-background-image:url(../../base/images/icons/icons-01.png);
+background-image:url(../../base/images/icons/icons-01.gif);
 background-repeat:no-repeat;
 background-color:transparent;
 }
diff --git a/theme/identica/css/display.css b/theme/identica/css/display.css
index 7d9f0ea2dc..f938618197 100644
--- a/theme/identica/css/display.css
+++ b/theme/identica/css/display.css
@@ -136,7 +136,7 @@ button.close,
 .form_user_unsubscribe input.submit,
 .form_group_join input.submit,
 .form_user_subscribe input.submit {
-background-image:url(../../base/images/icons/icons-01.png);
+background-image:url(../../base/images/icons/icons-01.gif);
 background-repeat:no-repeat;
 background-color:transparent;
 }