diff --git a/doc-src/HAML_CHANGELOG.md b/doc-src/HAML_CHANGELOG.md
index 18a99398..e20b90fc 100644
--- a/doc-src/HAML_CHANGELOG.md
+++ b/doc-src/HAML_CHANGELOG.md
@@ -11,6 +11,11 @@ Apparently the last version broke in new and exciting ways under Rails 3,
 due to the inconsistent load order caused by certain combinations of gems.
 3.0.12 hacks around that inconsistency, and *should* be fully Rails 3-compatible.
 
+### Deprecated: Rails 3 Beta 3
+
+Haml's support for Rails 3.0.0.beta.3 has been deprecated.
+Haml 3.0.13 will only support 3.0.0.beta.4.
+
 ## 3.0.11
 
 [Tagged on GitHub](http://github.com/nex3/haml/commit/3.0.11).
diff --git a/doc-src/SASS_CHANGELOG.md b/doc-src/SASS_CHANGELOG.md
index e939d7b8..18f4e846 100644
--- a/doc-src/SASS_CHANGELOG.md
+++ b/doc-src/SASS_CHANGELOG.md
@@ -11,6 +11,11 @@ Apparently the last version broke in new and exciting ways under Rails 3,
 due to the inconsistent load order caused by certain combinations of gems.
 3.0.12 hacks around that inconsistency, and *should* be fully Rails 3-compatible.
 
+### Deprecated: Rails 3 Beta 3
+
+Haml's support for Rails 3.0.0.beta.3 has been deprecated.
+Haml 3.0.13 will only support 3.0.0.beta.4.
+
 ## 3.0.11
 
 [Tagged on GitHub](http://github.com/nex3/haml/commit/3.0.11).
diff --git a/lib/sass/plugin/rails.rb b/lib/sass/plugin/rails.rb
index acc91e5f..bf9ec811 100644
--- a/lib/sass/plugin/rails.rb
+++ b/lib/sass/plugin/rails.rb
@@ -1,4 +1,13 @@
 unless defined?(Sass::RAILS_LOADED)
+  if Haml::Util.ap_geq_3? && !Haml::Util.ap_geq?("3.0.0.beta4")
+    Haml::Util.haml_warn(<<WARNING)
+DEPRECATION WARNING:
+Haml/Sass support for Rails 3 versions before beta 4 is deprecated,
+  and will be removed in Haml/Sass 3.0.13.
+  Please upgrade to Rails 3.0.0.beta4 or later.
+WARNING
+  end
+
   Sass::RAILS_LOADED = true
 
   # Reverse-merging (we're in Rails, anyway) so we dont' clobber what's already been defined further up-stream