diff --git a/src/file.cpp b/src/file.cpp
index 46973057a..32d4a7c63 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -323,7 +323,7 @@ namespace Sass {
     // (2) underscore + given
     // (3) underscore + given + extension
     // (4) given + extension
-    std::vector<Include> resolve_includes(const std::string& root, const std::string& file, const std::vector<std::string>& exts, const std::vector<std::string>& d_exts)
+    std::vector<Include> resolve_includes(const std::string& root, const std::string& file, const std::vector<std::string>& exts)
     {
       std::string filename = join_paths(root, file);
       // split the filename
@@ -350,18 +350,6 @@ namespace Sass {
         abs_path = join_paths(root, rel_path);
         if (file_exists(abs_path)) includes.push_back({{ rel_path, root }, abs_path });
       }
-      // next test d_exts plus underscore
-      for(auto ext : d_exts) {
-        rel_path = join_paths(base, "_" + name + ext);
-        abs_path = join_paths(root, rel_path);
-        if (file_exists(abs_path)) includes.push_back({{ rel_path, root }, abs_path });
-      }
-      // next test plain name with d_exts
-      for(auto ext : d_exts) {
-        rel_path = join_paths(base, name + ext);
-        abs_path = join_paths(root, rel_path);
-        if (file_exists(abs_path)) includes.push_back({{ rel_path, root }, abs_path });
-      }
       // nothing found
       return includes;
     }
diff --git a/src/file.hpp b/src/file.hpp
index 759996fa8..279b9e9f6 100644
--- a/src/file.hpp
+++ b/src/file.hpp
@@ -121,12 +121,10 @@ namespace Sass {
 
   namespace File {
 
-    static std::vector<std::string> defaultExtensions = { ".scss", ".sass" };
-    static std::vector<std::string> deprecatedExtensions = { ".css" };
+    static std::vector<std::string> defaultExtensions = { ".scss", ".sass", ".css" };
 
     std::vector<Include> resolve_includes(const std::string& root, const std::string& file,
-      const std::vector<std::string>& exts = defaultExtensions,
-      const std::vector<std::string>& d_exts = deprecatedExtensions);
+      const std::vector<std::string>& exts = defaultExtensions);
 
   }