diff --git a/Rakefile b/Rakefile
index 39149b607ad..ceac0627ab2 100644
--- a/Rakefile
+++ b/Rakefile
@@ -53,13 +53,10 @@ end
 
 # So `rake clobber` will delete generated files
 CLOBBER.concat(TEMPLATES)
-if RbConfig::CONFIG["host_os"] =~ /darwin/
-  so_ext = "dylib"
-else
-  so_ext = "so"
-end
-CLOBBER << "build/librubyparser.#{so_ext}"
-CLOBBER << "lib/yarp.so"
+
+dylib_extension = RbConfig::CONFIG["host_os"].match?(/darwin/) ? "dylib" : "so"
+CLOBBER << "build/librubyparser.#{dylib_extension}"
+CLOBBER << "lib/yarp.#{dylib_extension}"
 
 TEMPLATES.each do |filepath|
   desc "Template #{filepath}"
@@ -78,13 +75,6 @@ task lex: :compile do
   results = { passing: [], failing: [] }
   colorize = ->(code, string) { "\033[#{code}m#{string}\033[0m" }
 
-  accepted_encodings = [
-    Encoding::ASCII_8BIT,
-    Encoding::ISO_8859_9,
-    Encoding::US_ASCII,
-    Encoding::UTF_8
-  ]
-
   filepaths =
     if ENV["FILEPATHS"]
       Dir[ENV["FILEPATHS"]]
@@ -95,27 +85,13 @@ task lex: :compile do
   filepaths.each do |filepath|
     source = File.read(filepath)
 
-    # If this file can't be parsed at all, then don't try to compare it to
-    # ripper's output.
-    ripper = Ripper.new(source).tap(&:parse)
-    next if ripper.error?
-
-    # If this file has an encoding that we don't support, then don't try to
-    # compare it to ripper's output.
-    unless accepted_encodings.include?(ripper.encoding)
+    if YARP.lex_ripper(source) == YARP.lex_compat(source)
+      print colorize.call(32, ".")
+      results[:passing] << filepath
+    else
       print colorize.call(31, "E")
       results[:failing] << filepath
-      next
     end
-
-    result =
-      YARP.lex_ripper(source).zip(YARP.lex_compat(source)).all? do |(ripper, yarp)|
-        break false if yarp.nil?
-        ripper == yarp
-      end
-
-    print result ? colorize.call(32, ".") : colorize.call(31, "E")
-    results[result ? :passing : :failing] << filepath
   end
 
   puts "\n\nPASSING=#{results[:passing].length}\nFAILING=#{results[:failing].length}"
diff --git a/bin/templates/src/node.c.erb b/bin/templates/src/node.c.erb
index 16e9be51d0e..daedd7d6c34 100644
--- a/bin/templates/src/node.c.erb
+++ b/bin/templates/src/node.c.erb
@@ -159,10 +159,13 @@ yp_node_destroy(yp_parser_t *parser, yp_node_t *node) {
       <%- raise -%>
       <%- end -%>
       <%- end -%>
-      free(node);
       break;
     <%- end -%>
+    default:
+      assert(false && "unreachable");
+      break;
   }
+  free(node);
 }
 
 static void
diff --git a/ext/yarp/extension.c b/ext/yarp/extension.c
index 12638489e00..d1590106db4 100644
--- a/ext/yarp/extension.c
+++ b/ext/yarp/extension.c
@@ -128,7 +128,7 @@ lex_source(source_t *source) {
   };
 
   parser.lex_callback = &lex_callback;
-  yp_parse(&parser);
+  yp_node_destroy(&parser, yp_parse(&parser));
   yp_parser_free(&parser);
 
   return ary;
diff --git a/src/diagnostic.c b/src/diagnostic.c
index f190fe87c5b..ffab91cff89 100644
--- a/src/diagnostic.c
+++ b/src/diagnostic.c
@@ -13,13 +13,14 @@ yp_diagnostic_list_append(yp_list_t *list, const char *message, uint32_t positio
 // Deallocate the internal state of the given diagnostic list.
 void
 yp_diagnostic_list_free(yp_list_t *list) {
-  yp_list_node_t *node = list->head;
-  yp_list_node_t *next;
+  yp_list_node_t *node, *next;
 
-  while (node != NULL) {
+  for (node = list->head; node != NULL; node = next) {
     next = node->next;
-    yp_string_free(&((yp_diagnostic_t *) node)->message);
-    free(node);
-    node = next;
+
+    yp_diagnostic_t *diagnostic = (yp_diagnostic_t *) node;
+    yp_string_free(&diagnostic->message);
+
+    free(diagnostic);
   }
 }
diff --git a/src/yarp.c b/src/yarp.c
index b009aceac35..fb0fdef1757 100644
--- a/src/yarp.c
+++ b/src/yarp.c
@@ -5996,7 +5996,7 @@ parse_expression_infix(yp_parser_t *parser, yp_node_t *node, binding_power_t bin
             // need foo=. In this case we'll allocate a new owned string, copy
             // the previous method name in, and append an =.
             size_t length = yp_string_length(&node->as.call_node.name);
-            char *name = malloc(length + 1);
+            char *name = malloc(length + 2);
             sprintf(name, "%.*s=", (int) length, yp_string_source(&node->as.call_node.name));
 
             // Now switch the name to the new string.
@@ -6426,11 +6426,25 @@ yp_parser_register_encoding_decode_callback(yp_parser_t *parser, yp_encoding_dec
   parser->encoding_decode_callback = callback;
 }
 
+// Free all of the memory associated with the comment list.
+static inline void
+yp_comment_list_free(yp_list_t *list) {
+  yp_list_node_t *node, *next;
+
+  for (node = list->head; node != NULL; node = next) {
+    next = node->next;
+
+    yp_comment_t *comment = (yp_comment_t *) node;
+    free(comment);
+  }
+}
+
 // Free any memory associated with the given parser.
 __attribute__((__visibility__("default"))) extern void
 yp_parser_free(yp_parser_t *parser) {
   yp_diagnostic_list_free(&parser->error_list);
-  yp_list_free(&parser->comment_list);
+  yp_diagnostic_list_free(&parser->warning_list);
+  yp_comment_list_free(&parser->comment_list);
 }
 
 // Get the next token type and set its value on the current pointer.