diff --git a/include/libregex.h b/include/libregex.h
index e776d92..28339a5 100644
--- a/include/libregex.h
+++ b/include/libregex.h
@@ -301,7 +301,7 @@ void regex_node_clear(regex_node* node);
  * Frees an entire NFA, starting from the given root node.
  * @param root the root, or starting node, of the NFA.
  */
-void regex_free(regex_node* root);
+libregex_result regex_free(regex_node* root);
 /**
  * Builds a regular expression from the given regular expression strings.
  * @param root the root node to build into.
diff --git a/src/libregex.c b/src/libregex.c
index fbfbc29..68eda3c 100644
--- a/src/libregex.c
+++ b/src/libregex.c
@@ -78,6 +78,7 @@ libregex_result _regex_node_create_group(regex_node** open, regex_node** close,
   } else {
     free(*open);
     free(*close);
+    *open = *close = NULL;
   }
   return result;
 }
@@ -149,7 +150,7 @@ void _regex_chain_append_chain(regex_chain* append_to, regex_chain* to_append){
 
 libregex_result _regex_find_all(regex_node* node, ll* append_to, int tag_with){
   libregex_result result = LIBREGEX_SUCCESS;
-  if(node->list_id != tag_with){
+  if(node && node->list_id != tag_with){
     node->list_id = tag_with;
     if(node->type == REGEX_VALUE){
       result = _regex_find_all(node->data_u.value_s.next, append_to, tag_with);