diff --git a/lib/loofah/helpers.rb b/lib/loofah/helpers.rb
index 17400b17..4cdfa3a3 100644
--- a/lib/loofah/helpers.rb
+++ b/lib/loofah/helpers.rb
@@ -95,7 +95,9 @@ def sanitize_css style_string, *args
       end
 
       WhiteListSanitizer = SafeListSanitizer
-      deprecate_constant :WhiteListSanitizer
+      if Object.respond_to?(:deprecate_constant)
+        deprecate_constant :WhiteListSanitizer
+      end
     end
   end
 end
diff --git a/lib/loofah/html5/safelist.rb b/lib/loofah/html5/safelist.rb
index 3144d352..558dea9c 100644
--- a/lib/loofah/html5/safelist.rb
+++ b/lib/loofah/html5/safelist.rb
@@ -787,7 +787,9 @@ module SafeList
     end
 
     WhiteList = SafeList
-    deprecate_constant :WhiteList
+    if Object.respond_to?(:deprecate_constant)
+      deprecate_constant :WhiteList
+    end
 
     ::Loofah::MetaHelpers.add_downcased_set_members_to_all_set_constants ::Loofah::HTML5::SafeList
   end