diff --git a/cli/src/main.rs b/cli/src/main.rs
index 347d842d..2bb290eb 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -77,6 +77,10 @@ fn run() -> Result<()> {
         .long("quiet")
         .short("q");
 
+    let wasm_arg = Arg::with_name("wasm")
+        .long("wasm")
+        .help("compile parsers to wasm instead of native dynamic libraries");
+
     let matches = App::new("tree-sitter")
         .author("Max Brunsfeld <maxbrunsfeld@gmail.com>")
         .about("Generates and tests parsers")
@@ -125,7 +129,7 @@ fn run() -> Result<()> {
                 .arg(&debug_arg)
                 .arg(&debug_build_arg)
                 .arg(&debug_graph_arg)
-                .arg(Arg::with_name("wasm").long("wasm").help("use wasm file"))
+                .arg(&wasm_arg)
                 .arg(Arg::with_name("debug-xml").long("xml").short("x"))
                 .arg(
                     Arg::with_name("stat")
@@ -201,7 +205,8 @@ fn run() -> Result<()> {
                 )
                 .arg(&debug_arg)
                 .arg(&debug_build_arg)
-                .arg(&debug_graph_arg),
+                .arg(&debug_graph_arg)
+                .arg(&wasm_arg),
         )
         .subcommand(
             SubCommand::with_name("highlight")
@@ -308,13 +313,25 @@ fn run() -> Result<()> {
             let debug_build = matches.is_present("debug-build");
             let update = matches.is_present("update");
             let filter = matches.value_of("filter");
+            let wasm = matches.is_present("wasm");
+            let mut parser = Parser::new();
 
             loader.use_debug_build(debug_build);
 
+            if wasm {
+                let engine = tree_sitter::wasmtime::Engine::default();
+                parser
+                    .set_wasm_store(WasmStore::new(engine.clone()))
+                    .unwrap();
+                loader.use_wasm(engine);
+            }
+
             let languages = loader.languages_at_path(&current_dir)?;
             let language = languages
                 .first()
                 .ok_or_else(|| anyhow!("No language found"))?;
+            parser.set_language(*language)?;
+
             let test_dir = current_dir.join("test");
 
             // Run the corpus tests. Look for them at two paths: `test/corpus` and `corpus`.
@@ -324,7 +341,7 @@ fn run() -> Result<()> {
             }
             if test_corpus_dir.is_dir() {
                 test::run_tests_at_path(
-                    *language,
+                    &mut parser,
                     &test_corpus_dir,
                     debug,
                     debug_graph,
diff --git a/cli/src/test.rs b/cli/src/test.rs
index 69c4a663..1ab57dcf 100644
--- a/cli/src/test.rs
+++ b/cli/src/test.rs
@@ -55,7 +55,7 @@ impl Default for TestEntry {
 }
 
 pub fn run_tests_at_path(
-    language: Language,
+    parser: &mut Parser,
     path: &Path,
     debug: bool,
     debug_graph: bool,
@@ -64,11 +64,9 @@ pub fn run_tests_at_path(
 ) -> Result<()> {
     let test_entry = parse_tests(path)?;
     let mut _log_session = None;
-    let mut parser = Parser::new();
-    parser.set_language(language)?;
 
     if debug_graph {
-        _log_session = Some(util::log_graphs(&mut parser, "log.html")?);
+        _log_session = Some(util::log_graphs(parser, "log.html")?);
     } else if debug {
         parser.set_logger(Some(Box::new(|log_type, message| {
             if log_type == LogType::Lex {
@@ -81,7 +79,7 @@ pub fn run_tests_at_path(
     let mut failures = Vec::new();
     let mut corrected_entries = Vec::new();
     run_tests(
-        &mut parser,
+        parser,
         test_entry,
         filter,
         0,
diff --git a/lib/src/parser.c b/lib/src/parser.c
index 12605b37..7e0448ee 100644
--- a/lib/src/parser.c
+++ b/lib/src/parser.c
@@ -1865,13 +1865,24 @@ const TSLanguage *ts_parser_language(const TSParser *self) {
 }
 
 bool ts_parser_set_language(TSParser *self, const TSLanguage *language) {
-  if (language) {
-    if (language->version > TREE_SITTER_LANGUAGE_VERSION) return false;
-    if (language->version < TREE_SITTER_MIN_COMPATIBLE_LANGUAGE_VERSION) return false;
-  }
   ts_parser__external_scanner_destroy(self);
+  self->language = NULL;
+
+  if (language) {
+    if (
+      language->version > TREE_SITTER_LANGUAGE_VERSION ||
+      language->version < TREE_SITTER_MIN_COMPATIBLE_LANGUAGE_VERSION
+    ) return false;
+
+    if (ts_language_is_wasm(language)) {
+      if (
+        !self->wasm_store ||
+        !ts_wasm_store_start(self->wasm_store, &self->lexer.data, language)
+      ) return false;
+    }
+  }
+
   self->language = language;
-  ts_wasm_store_start(self->wasm_store, &self->lexer.data, language);
   ts_parser__external_scanner_create(self);
   ts_parser_reset(self);
   return true;
diff --git a/lib/src/wasm.c b/lib/src/wasm.c
index c6f320c7..864eb69e 100644
--- a/lib/src/wasm.c
+++ b/lib/src/wasm.c
@@ -819,11 +819,11 @@ const TSLanguage *ts_wasm_store_load_language(
     ),
     .symbol_metadata = copy(
       &memory[wasm_language.symbol_metadata],
-      wasm_language.symbol_count * sizeof(TSSymbolMetadata)
+      (wasm_language.symbol_count + wasm_language.alias_count) * sizeof(TSSymbolMetadata)
     ),
     .public_symbol_map = copy(
       &memory[wasm_language.public_symbol_map],
-      wasm_language.symbol_count * sizeof(TSSymbol)
+      (wasm_language.symbol_count + wasm_language.alias_count) * sizeof(TSSymbol)
     ),
     .lex_modes = copy(
       &memory[wasm_language.lex_modes],
@@ -884,6 +884,13 @@ const TSLanguage *ts_wasm_store_load_language(
     );
   }
 
+  if (language->version >= 14) {
+    language->primary_state_ids = copy(
+      &memory[wasm_language.primary_state_ids],
+      wasm_language.state_count * sizeof(TSStateId)
+    );
+  }
+
   if (language->external_token_count > 0) {
     language->external_scanner.symbol_map = copy(
       &memory[wasm_language.external_scanner.symbol_map],
@@ -985,8 +992,6 @@ bool ts_wasm_store_add_language(
 
 bool ts_wasm_store_start(TSWasmStore *self, TSLexer *lexer, const TSLanguage *language) {
   uint32_t instance_index;
-  if (!language) return false;
-  if (!ts_language_is_wasm(language)) return false;
   if (!ts_wasm_store_add_language(self, language, &instance_index)) return false;
   self->current_lexer = lexer;
   self->current_instance = &self->language_instances.contents[instance_index];