diff --git a/src/bitwriter.c b/src/bitwriter.c
index a6d06ca..c24ef0e 100644
--- a/src/bitwriter.c
+++ b/src/bitwriter.c
@@ -104,6 +104,7 @@ void h_bit_writer_free(HBitWriter* w) {
   g_free(w);
 }
 
+#ifdef INCLUDE_TESTS
 // TESTS BELOW HERE
 typedef struct {
   unsigned long long data;
@@ -134,3 +135,43 @@ void run_bitwriter_test(bitwriter_test_elem data[], char flags) {
     g_check_cmpulonglong ((unsigned long long)h_read_bits(&input, data[i].nbits, FALSE), ==,  data[i].data);
   }
 }
+
+static void test_bitwriter_ints(void) {
+
+}
+
+static void test_bitwriter_be(void) {
+
+}
+
+static void test_bitwriter_le(void) {
+
+}
+
+static void test_largebits_be(void) {
+
+}
+
+static void test_largebits_le(void) {
+
+}
+
+static void test_offset_largebits_be(void) {
+
+}
+
+static void test_offset_largebits_le(void) {
+
+}
+
+void register_bitwriter_tests(void) {
+  g_test_add_func("/core/bitwriter/be", test_bitwriter_be);
+  g_test_add_func("/core/bitwriter/le", test_bitwriter_le);
+  g_test_add_func("/core/bitwriter/largebits-be", test_largebits_be);
+  g_test_add_func("/core/bitwriter/largebits-le", test_largebits_le);
+  g_test_add_func("/core/bitwriter/offset-largebits-be", test_offset_largebits_be);
+  g_test_add_func("/core/bitwriter/offset-largebits-le", test_offset_largebits_le);
+  g_test_add_func("/core/bitwriter/ints", test_bitwriter_ints);
+}
+
+#endif // #ifdef INCLUDE_TESTS
diff --git a/src/hammer.c b/src/hammer.c
index 904fdd0..82ca235 100644
--- a/src/hammer.c
+++ b/src/hammer.c
@@ -265,6 +265,10 @@ HParseResult* h_parse(const HParser* parser, const uint8_t* input, size_t length
   return res;
 }
 
+void h_parse_result_free(HParseResult *result) {
+  h_delete_arena(result->arena);
+}
+
 #ifdef INCLUDE_TESTS
 
 #include "test_suite.h"
@@ -427,6 +431,7 @@ static void test_action(void) {
   
   g_check_parse_ok(action_, "ab", 2, "(u0x41 u0x42)");
   g_check_parse_ok(action_, "AB", 2, "(u0x41 u0x42)");
+  g_check_parse_failed(action_, "XX", 2);
 }
 
 static void test_not_in(void) {
diff --git a/src/hammer.h b/src/hammer.h
index 26367f3..fc3ea5b 100644
--- a/src/hammer.h
+++ b/src/hammer.h
@@ -443,6 +443,11 @@ HParser *h_indirect();
  */
 void h_bind_indirect(HParser* indirect, HParser* inner);
 
+/**
+ * Free the memory allocated to an HParseResult when it is no longer needed.
+ */
+void h_parse_result_free(HParseResult *result);
+
 // Some debugging aids
 /**
  * Format token into a compact unambiguous form. Useful for parser test cases.
diff --git a/src/parsers/action.c b/src/parsers/action.c
index c5b89f9..479a840 100644
--- a/src/parsers/action.c
+++ b/src/parsers/action.c
@@ -10,8 +10,11 @@ static HParseResult* parse_action(void *env, HParseState *state) {
   if (a->p && a->action) {
     HParseResult *tmp = h_do_parse(a->p, state);
     //HParsedToken *tok = a->action(h_do_parse(a->p, state));
-    const HParsedToken *tok = a->action(tmp);
-    return make_result(state, (HParsedToken*)tok);
+    if(tmp) {
+        const HParsedToken *tok = a->action(tmp);
+        return make_result(state, (HParsedToken*)tok);
+    } else
+      return NULL;
   } else // either the parser's missing or the action's missing
     return NULL;
 }
diff --git a/src/test_suite.c b/src/test_suite.c
index 016274c..af22c7e 100644
--- a/src/test_suite.c
+++ b/src/test_suite.c
@@ -19,6 +19,7 @@
 #include "test_suite.h"
 
 extern void register_bitreader_tests();
+extern void register_bitwriter_tests();
 extern void register_parser_tests();
 
 int main(int argc, char** argv) {
@@ -26,6 +27,7 @@ int main(int argc, char** argv) {
 
   // register various test suites...
   register_bitreader_tests();
+  register_bitwriter_tests();
   register_parser_tests();
 
   g_test_run();