diff --git a/src/tokens.c b/src/tokens.c
index 3fd6a949..6c7ae94b 100644
--- a/src/tokens.c
+++ b/src/tokens.c
@@ -6,7 +6,6 @@ tokenized_string_t *tokenized_string_new(void) {
     self->str = NULL;
     self->strings = cstring_array_new();
     self->tokens = token_array_new();
-
     return self;
 }
 
@@ -21,7 +20,7 @@ tokenized_string_t *tokenized_string_new_size(size_t len, size_t num_tokens) {
 
 inline tokenized_string_t *tokenized_string_new_from_str_size(char *src, size_t len, size_t num_tokens) {
     tokenized_string_t *self = tokenized_string_new_size(len, num_tokens);
-    self->str = src;
+    self->str = strndup(src);
     return self;
 }
 
@@ -38,7 +37,7 @@ void tokenized_string_add_token(tokenized_string_t *self, const char *src, size_
 
 tokenized_string_t *tokenized_string_from_tokens(char *src, token_array *tokens, bool copy_tokens) {
     tokenized_string_t *self = malloc(sizeof(tokenized_string_t));
-    self->str = src;
+    self->str = stdup(src);
     self->strings = cstring_array_new_size(strlen(src) + tokens->n);
     if (copy_tokens) {
         self->tokens = token_array_new_copy(tokens, tokens->n);
@@ -48,7 +47,7 @@ tokenized_string_t *tokenized_string_from_tokens(char *src, token_array *tokens,
 
     token_t token;
 
-    for (int i = 0; i < tokens->n; i++) {
+    for (size_t i = 0; i < tokens->n; i++) {
         token = tokens->a[i];
         cstring_array_add_string_len(self->strings, src + token.offset, token.len);
     }