diff --git a/.travis.yml b/.travis.yml
index 66dbd0f1..7c4b84ce 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,5 @@
 language: cpp
 compiler:
-    - clang
+    - gcc
 install: script/configure.sh
 script: script/test.sh
diff --git a/spec/runtime/helpers/read_test_entries.cc b/spec/runtime/helpers/read_test_entries.cc
index 58b47b27..d5c0301b 100644
--- a/spec/runtime/helpers/read_test_entries.cc
+++ b/spec/runtime/helpers/read_test_entries.cc
@@ -48,9 +48,9 @@ static vector<TestEntry> get_test_entries_from_string(string content) {
         std::smatch matches;
         regex_search(body, matches, separator_pattern);
         result.push_back({
-            .description = descriptions[i],
-            .input = body.substr(0, matches.position()),
-            .tree_string = trim_output(body.substr(matches.position() + matches[0].length()))
+            descriptions[i],
+            body.substr(0, matches.position()),
+            trim_output(body.substr(matches.position() + matches[0].length()))
         });
     }
 
diff --git a/spec/runtime/helpers/spy_reader.cc b/spec/runtime/helpers/spy_reader.cc
index 927f3ac2..27f0201a 100644
--- a/spec/runtime/helpers/spy_reader.cc
+++ b/spec/runtime/helpers/spy_reader.cc
@@ -31,8 +31,8 @@ SpyReader::SpyReader(string content, size_t chunk_size) :
     position(0),
     chunk_size(chunk_size),
     input({
-        .read_fn = spy_read,
-        .seek_fn = spy_seek,
-        .release_fn = spy_release,
-        .data = this
+        this,
+        spy_read,
+        spy_seek,
+        spy_release,
     }) {}
diff --git a/spec/runtime/parser_spec.cc b/spec/runtime/parser_spec.cc
index 6135c1c8..300c2a4a 100644
--- a/spec/runtime/parser_spec.cc
+++ b/spec/runtime/parser_spec.cc
@@ -39,11 +39,7 @@ describe("incremental parsing", [&]() {
             string inserted_text(", \"key2\": 4");
 
             reader->content.insert(position, inserted_text);
-            ts_document_edit(doc, {
-                .position = position,
-                .bytes_removed = 0,
-                .bytes_inserted = inserted_text.length()
-            });
+            ts_document_edit(doc, { position, 0, inserted_text.length() });
         });
 
         it("updates the parse tree", [&]() {
@@ -63,11 +59,7 @@ describe("incremental parsing", [&]() {
             string inserted_text("\"key2\": 4, ");
 
             reader->content.insert(position, inserted_text);
-            ts_document_edit(doc, {
-                .position = position,
-                .bytes_removed = 0,
-                .bytes_inserted = inserted_text.length()
-            });
+            ts_document_edit(doc, { position, 0, inserted_text.length() });
         });
 
         it("2 updates the parse tree", [&]() {
diff --git a/src/compiler/build_tables/conflict_manager.cc b/src/compiler/build_tables/conflict_manager.cc
index c2df0121..753f0689 100644
--- a/src/compiler/build_tables/conflict_manager.cc
+++ b/src/compiler/build_tables/conflict_manager.cc
@@ -23,9 +23,8 @@ namespace tree_sitter {
                 }
                 case ParseActionTypeAccept:
                     return "accept";
-                case ParseActionTypeError:
+                default:
                     return "error";
-                    break;
             }
         }
 
diff --git a/src/compiler/generate_code/c_code.cc b/src/compiler/generate_code/c_code.cc
index 60f62094..40d3a92c 100644
--- a/src/compiler/generate_code/c_code.cc
+++ b/src/compiler/generate_code/c_code.cc
@@ -142,6 +142,8 @@ namespace tree_sitter {
                         return "ACCEPT_TOKEN(" + symbol_id(action.symbol) + ");";
                     case LexActionTypeError:
                         return "LEX_ERROR();";
+                    default:
+                        return "";
                 }
             }
 
diff --git a/src/compiler/lex_table.cc b/src/compiler/lex_table.cc
index 273e2c45..056f1ff6 100644
--- a/src/compiler/lex_table.cc
+++ b/src/compiler/lex_table.cc
@@ -8,7 +8,10 @@ namespace tree_sitter {
     using rules::Symbol;
     using rules::CharacterSet;
 
-    LexAction::LexAction() : LexAction(LexActionTypeError, -1, Symbol("")) {}
+    LexAction::LexAction() :
+        type(LexActionTypeError),
+        symbol(Symbol("")),
+        state_index(-1) {}
 
     LexAction::LexAction(LexActionType type, size_t state_index, Symbol symbol) :
         type(type),
@@ -42,6 +45,8 @@ namespace tree_sitter {
                 return stream << string("#<accept ") + action.symbol.name + ">";
             case LexActionTypeAdvance:
                 return stream << string("#<advance ") + to_string(action.state_index) + ">";
+            default:
+                return stream;
         }
     }
 
diff --git a/src/compiler/parse_table.cc b/src/compiler/parse_table.cc
index 2414806e..0c71f317 100644
--- a/src/compiler/parse_table.cc
+++ b/src/compiler/parse_table.cc
@@ -18,7 +18,11 @@ namespace tree_sitter {
         state_index(state_index),
         consumed_symbol_count(consumed_symbol_count) {}
 
-    ParseAction::ParseAction() : ParseAction(ParseActionTypeError, -1, Symbol(""), {}) {}
+    ParseAction::ParseAction() :
+        type(ParseActionTypeError),
+        symbol(Symbol("")),
+        state_index(-1),
+        consumed_symbol_count(0) {}
 
     ParseAction ParseAction::Error() {
         return ParseAction(ParseActionTypeError, -1, Symbol(""), {});
@@ -53,6 +57,8 @@ namespace tree_sitter {
                 return stream << (string("#<shift ") + to_string(action.state_index) + ">");
             case ParseActionTypeReduce:
                 return stream << (string("#<reduce ") + action.symbol.name + ">");
+            default:
+                return stream;
         }
     }
 
diff --git a/src/compiler/rules/symbol.cc b/src/compiler/rules/symbol.cc
index 96b92a33..babc8100 100644
--- a/src/compiler/rules/symbol.cc
+++ b/src/compiler/rules/symbol.cc
@@ -36,6 +36,8 @@ namespace tree_sitter  {
                     return string("#<aux_sym '") + name + "'>";
                 case SymbolTypeBuiltIn:
                     return string("#<builtin_sym '") + name + "'>";
+                default:
+                    return "";
             }
         }
 
diff --git a/tree_sitter.gyp b/tree_sitter.gyp
index 646a0fd2..c8a470e9 100644
--- a/tree_sitter.gyp
+++ b/tree_sitter.gyp
@@ -77,8 +77,11 @@
       '-Wextra',
       '-Wno-unused-parameter'
     ],
+    'cflags_c': [
+      '-std=c99'
+    ],
     'cflags_cc': [
-      '-std=c++11',
+      '-std=c++0x',
     ],
     'xcode_settings': {
       'CLANG_CXX_LANGUAGE_STANDARD': 'c++11',