diff --git a/include/tree_sitter/parser.h b/include/tree_sitter/parser.h
index e1872ab4..09c09c54 100644
--- a/include/tree_sitter/parser.h
+++ b/include/tree_sitter/parser.h
@@ -80,12 +80,19 @@ typedef union {
   unsigned int count;
 } TSParseActionEntry;
 
+typedef union {
+  TSSymbol symbol;
+  unsigned int count;
+} TSInProgressSymbolEntry;
+
 struct TSLanguage {
   size_t symbol_count;
   const char **symbol_names;
   const TSSymbolMetadata *symbol_metadata;
   const unsigned short *parse_table;
   const TSParseActionEntry *parse_actions;
+  const unsigned short *in_progress_symbol_table;
+  const TSInProgressSymbolEntry *in_progress_symbols;
   const TSStateId *lex_states;
   TSTree *(*lex_fn)(TSLexer *, TSStateId, bool);
 };
@@ -181,19 +188,21 @@ enum {
     { .type = TSParseActionTypeAccept } \
   }
 
-#define EXPORT_LANGUAGE(language_name)                     \
-  static TSLanguage language = {                           \
-    .symbol_count = SYMBOL_COUNT,                          \
-    .symbol_metadata = ts_symbol_metadata,                 \
-    .parse_table = (const unsigned short *)ts_parse_table, \
-    .parse_actions = ts_parse_actions,                     \
-    .lex_states = ts_lex_states,                           \
-    .symbol_names = ts_symbol_names,                       \
-    .lex_fn = ts_lex,                                      \
-  };                                                       \
-                                                           \
-  const TSLanguage *language_name() {                      \
-    return &language;                                      \
+#define EXPORT_LANGUAGE(language_name)                       \
+  static TSLanguage language = {                             \
+    .symbol_count = SYMBOL_COUNT,                            \
+    .symbol_metadata = ts_symbol_metadata,                   \
+    .parse_table = (const unsigned short *)ts_parse_table,   \
+    .parse_actions = ts_parse_actions,                       \
+    .in_progress_symbol_table = ts_in_progress_symbol_table, \
+    .in_progress_symbols = ts_in_progress_symbols,           \
+    .lex_states = ts_lex_states,                             \
+    .symbol_names = ts_symbol_names,                         \
+    .lex_fn = ts_lex,                                        \
+  };                                                         \
+                                                             \
+  const TSLanguage *language_name() {                        \
+    return &language;                                        \
   }
 
 #ifdef __cplusplus
diff --git a/src/compiler/build_tables/build_parse_table.cc b/src/compiler/build_tables/build_parse_table.cc
index 2592e5e3..634a5afd 100644
--- a/src/compiler/build_tables/build_parse_table.cc
+++ b/src/compiler/build_tables/build_parse_table.cc
@@ -131,6 +131,12 @@ class ParseTableBuilder {
     auto pair = parse_state_ids.find(item_set);
     if (pair == parse_state_ids.end()) {
       ParseStateId state_id = parse_table.add_state();
+      for (const auto &entry : item_set.entries) {
+        const ParseItem &item = entry.first;
+        if (item.step_index > 0 && item.lhs() != rules::START())
+          parse_table.states[state_id].in_progress_symbols.insert(item.lhs());
+      }
+
       parse_state_ids[item_set] = state_id;
       item_sets_to_process.push_back({ item_set, state_id });
       return state_id;
diff --git a/src/compiler/generate_code/c_code.cc b/src/compiler/generate_code/c_code.cc
index 1e09a977..3819e0b2 100644
--- a/src/compiler/generate_code/c_code.cc
+++ b/src/compiler/generate_code/c_code.cc
@@ -74,7 +74,9 @@ class CCodeGenerator {
   const LexicalGrammar lexical_grammar;
   map<string, string> sanitized_names;
   vector<pair<size_t, vector<ParseAction>>> parse_actions;
+  vector<pair<size_t, set<rules::Symbol>>> in_progress_symbols;
   size_t next_parse_action_list_index;
+  size_t next_in_progress_symbol_list_index;
 
  public:
   CCodeGenerator(string name, const ParseTable &parse_table,
@@ -86,7 +88,8 @@ class CCodeGenerator {
         lex_table(lex_table),
         syntax_grammar(syntax_grammar),
         lexical_grammar(lexical_grammar),
-        next_parse_action_list_index(0) {}
+        next_parse_action_list_index(0),
+        next_in_progress_symbol_list_index(0) {}
 
   string code() {
     buffer = "";
@@ -100,6 +103,7 @@ class CCodeGenerator {
     add_lex_states_list();
     add_out_of_context_parse_states_list();
     add_parse_table();
+    add_in_progress_symbol_table();
     add_parser_export();
 
     return buffer;
@@ -233,7 +237,7 @@ class CCodeGenerator {
   }
 
   void add_parse_table() {
-    add_parse_actions({ ParseAction::Error() });
+    add_parse_action_list_id({ ParseAction::Error() });
 
     size_t state_id = 0;
     line("#pragma GCC diagnostic push");
@@ -247,7 +251,7 @@ class CCodeGenerator {
         indent([&]() {
           for (const auto &pair : state.actions) {
             line("[" + symbol_id(pair.first) + "] = ");
-            add(to_string(add_parse_actions(pair.second)));
+            add(to_string(add_parse_action_list_id(pair.second)));
             add(",");
           }
         });
@@ -263,6 +267,25 @@ class CCodeGenerator {
     line();
   }
 
+  void add_in_progress_symbol_table() {
+    line("static unsigned short ts_in_progress_symbol_table[] = {");
+
+    indent([&]() {
+      size_t state_id = 0;
+      for (const ParseState &state : parse_table.states) {
+        line("[" + to_string(state_id) + "] = ");
+        add(to_string(add_in_progress_symbol_list_id(state.in_progress_symbols)));
+        add(",");
+        state_id++;
+      }
+    });
+
+    line("};");
+    line();
+    add_in_progress_symbols_list();
+    line();
+  }
+
   void add_parser_export() {
     line("EXPORT_LANGUAGE(ts_language_" + name + ");");
     line();
@@ -345,7 +368,6 @@ class CCodeGenerator {
              to_string(pair.second.size()) + "},");
 
         for (const ParseAction &action : pair.second) {
-          index++;
           add(" ");
           switch (action.type) {
             case ParseActionTypeError:
@@ -383,7 +405,27 @@ class CCodeGenerator {
     line("};");
   }
 
-  size_t add_parse_actions(const vector<ParseAction> &actions) {
+  void add_in_progress_symbols_list() {
+    line("static TSInProgressSymbolEntry ts_in_progress_symbols[] = {");
+
+    indent([&]() {
+      for (const auto &pair : in_progress_symbols) {
+        size_t index = pair.first;
+        line("[" + to_string(index) + "] = {.count = " +
+             to_string(pair.second.size()) + "},");
+
+        for (const rules::Symbol &symbol : pair.second) {
+          add(" ");
+          add("{" + symbol_id(symbol) + "}");
+          add(",");
+        }
+      }
+    });
+
+    line("};");
+  }
+
+  size_t add_parse_action_list_id(const vector<ParseAction> &actions) {
     for (const auto &pair : parse_actions) {
       if (pair.second == actions) {
         return pair.first;
@@ -396,6 +438,19 @@ class CCodeGenerator {
     return result;
   }
 
+  size_t add_in_progress_symbol_list_id(const set<rules::Symbol> &symbols) {
+    for (const auto &pair : in_progress_symbols) {
+      if (pair.second == symbols) {
+        return pair.first;
+      }
+    }
+
+    size_t result = next_in_progress_symbol_list_index;
+    in_progress_symbols.push_back({ result, symbols });
+    next_in_progress_symbol_list_index += 1 + symbols.size();
+    return result;
+  }
+
   void add_action_flags(const ParseAction &action) {
     if (action.fragile && action.can_hide_split)
       add("FRAGILE|CAN_HIDE_SPLIT");
diff --git a/src/compiler/parse_table.h b/src/compiler/parse_table.h
index d3dba182..99232707 100644
--- a/src/compiler/parse_table.h
+++ b/src/compiler/parse_table.h
@@ -84,6 +84,7 @@ class ParseState {
   void each_advance_action(std::function<void(ParseAction *)>);
 
   std::map<rules::Symbol, std::vector<ParseAction>> actions;
+  std::set<rules::Symbol> in_progress_symbols;
   LexStateId lex_state_id;
 };