diff --git a/ast.hpp b/ast.hpp
index 12e3be473f..e4d37f93ef 100644
--- a/ast.hpp
+++ b/ast.hpp
@@ -431,10 +431,10 @@ namespace Sass {
   // Keyframe-rules -- the child blocks of "@keyframes" nodes.
   ///////////////////////////////////////////////////////////////////////
   class Keyframe_Rule : public Has_Block {
-    ADD_PROPERTY(String*, rules);
+    ADD_PROPERTY(Selector*, selector);
   public:
     Keyframe_Rule(ParserState pstate, Block* b)
-    : Has_Block(pstate, b), rules_(0)
+    : Has_Block(pstate, b), selector_(0)
     { statement_type(KEYFRAMERULE); }
     ATTACH_OPERATIONS();
   };
diff --git a/cssize.cpp b/cssize.cpp
index b00225a370..86738ccce2 100644
--- a/cssize.cpp
+++ b/cssize.cpp
@@ -87,7 +87,7 @@ namespace Sass {
 
     Keyframe_Rule* rr = new (ctx.mem) Keyframe_Rule(r->pstate(),
                                                     r->block()->perform(this)->block());
-    if (r->rules()) rr->rules(r->rules());
+    if (r->selector()) rr->selector(r->selector());
 
     return debubble(rr->block(), rr)->block();
   }
diff --git a/debugger.hpp b/debugger.hpp
index e000e2fe3f..7c75023ae6 100644
--- a/debugger.hpp
+++ b/debugger.hpp
@@ -219,6 +219,11 @@ inline void debug_ast(AST_Node* node, string ind = "", Env* env = 0)
     cerr << ind << "Declaration " << block << " " << block->tabs() << endl;
     debug_ast(block->property(), ind + " prop: ", env);
     debug_ast(block->value(), ind + " value: ", env);
+  } else if (dynamic_cast<Keyframe_Rule*>(node)) {
+    Keyframe_Rule* has_block = dynamic_cast<Keyframe_Rule*>(node);
+    cerr << ind << "Keyframe_Rule " << has_block << " " << has_block->tabs() << endl;
+    if (has_block->selector()) debug_ast(has_block->selector(), ind + "@");
+    if (has_block->block()) for(auto i : has_block->block()->elements()) { debug_ast(i, ind + " ", env); }
   } else if (dynamic_cast<At_Rule*>(node)) {
     At_Rule* block = dynamic_cast<At_Rule*>(node);
     cerr << ind << "At_Rule " << block << " [" << block->keyword() << "] " << block->tabs() << endl;
@@ -342,7 +347,20 @@ inline void debug_ast(AST_Node* node, string ind = "", Env* env = 0)
       endl;
   } else if (dynamic_cast<Expression*>(node)) {
     Expression* expression = dynamic_cast<Expression*>(node);
-    cerr << ind << "Expression " << expression << " " << expression->concrete_type() << endl;
+    cerr << ind << "Expression " << expression;
+    switch (expression->concrete_type()) {
+      case Expression::Concrete_Type::NONE: cerr << " [NONE]"; break;
+      case Expression::Concrete_Type::BOOLEAN: cerr << " [BOOLEAN]"; break;
+      case Expression::Concrete_Type::NUMBER: cerr << " [NUMBER]"; break;
+      case Expression::Concrete_Type::COLOR: cerr << " [COLOR]"; break;
+      case Expression::Concrete_Type::STRING: cerr << " [STRING]"; break;
+      case Expression::Concrete_Type::LIST: cerr << " [LIST]"; break;
+      case Expression::Concrete_Type::MAP: cerr << " [MAP]"; break;
+      case Expression::Concrete_Type::SELECTOR: cerr << " [SELECTOR]"; break;
+      case Expression::Concrete_Type::NULL_VAL: cerr << " [NULL_VAL]"; break;
+      case Expression::Concrete_Type::NUM_TYPES: cerr << " [NUM_TYPES]"; break;
+    }
+    cerr << endl;
   } else if (dynamic_cast<Has_Block*>(node)) {
     Has_Block* has_block = dynamic_cast<Has_Block*>(node);
     cerr << ind << "Has_Block " << has_block << " " << has_block->tabs() << endl;
diff --git a/expand.cpp b/expand.cpp
index dd08dc69b9..08d461d303 100644
--- a/expand.cpp
+++ b/expand.cpp
@@ -47,11 +47,7 @@ namespace Sass {
     if (in_keyframes) {
       To_String to_string;
       Keyframe_Rule* k = new (ctx.mem) Keyframe_Rule(r->pstate(), r->block()->perform(this)->block());
-      if (r->selector()) {
-        string s(r->selector()->perform(eval->with(env, backtrace))->perform(&to_string));
-        String_Constant* ss = new (ctx.mem) String_Constant(r->selector()->pstate(), s);
-        k->rules(ss);
-      }
+      if (r->selector()) k->selector(r->selector()->perform(contextualize_eval->with(0, env, backtrace)));
       in_at_root = old_in_at_root;
       old_in_at_root = false;
       return k;
diff --git a/inspect.cpp b/inspect.cpp
index f807613297..f2056c8d1c 100644
--- a/inspect.cpp
+++ b/inspect.cpp
@@ -44,9 +44,8 @@ namespace Sass {
 
   void Inspect::operator()(Keyframe_Rule* rule)
   {
-    append_indentation();
-    if (rule->rules()) rule->rules()->perform(this);
-    rule->block()->perform(this);
+    if (rule->selector()) rule->selector()->perform(this);
+    if (rule->block()) rule->block()->perform(this);
   }
 
   void Inspect::operator()(Propset* propset)
diff --git a/output.cpp b/output.cpp
index ce42d6c762..2468471771 100644
--- a/output.cpp
+++ b/output.cpp
@@ -172,11 +172,10 @@ namespace Sass {
 
   void Output::operator()(Keyframe_Rule* r)
   {
-    String* v = r->rules();
     Block* b = r->block();
+    Selector* v = r->selector();
 
     if (v) {
-      append_indentation();
       v->perform(this);
     }