diff --git a/run.c b/run.c
index afe695f..14469ad 100644
--- a/run.c
+++ b/run.c
@@ -508,6 +508,7 @@ void error_usage() {
     fprintf(stderr, "  -s <int>    random seed, default time(NULL)\n");
     fprintf(stderr, "  -n <int>    number of steps to run for, default 256. 0 = max_seq_len\n");
     fprintf(stderr, "  -i <string> input prompt\n");
+    fprintf(stderr, "  -z <string> optional path to custom tokenizer\n");
     exit(EXIT_FAILURE);
 }
 
@@ -515,6 +516,7 @@ int main(int argc, char *argv[]) {
 
     // default inits
     char *checkpoint = NULL;  // e.g. out/model.bin
+    char *tokenizer = "tokenizer.bin";
     float temperature = 1.0f; // 0.0 = greedy deterministic. 1.0 = original. don't set higher
     float topp = 1.0f;        // top-p in nucleus sampling. 1.0 = off. 0.9 works well, but slower
     rng_seed = 0; // seed rng with time by default
@@ -534,6 +536,7 @@ int main(int argc, char *argv[]) {
         else if (argv[i][1] == 's') { rng_seed = atoi(argv[i + 1]); }
         else if (argv[i][1] == 'n') { steps = atoi(argv[i + 1]); }
         else if (argv[i][1] == 'i') { prompt = argv[i + 1]; }
+        else if (argv[i][1] == 'z') { tokenizer = argv[i + 1]; }
         else { error_usage(); }
     }
     if(rng_seed == 0) { rng_seed =  (unsigned int)time(NULL);}
@@ -567,13 +570,13 @@ int main(int argc, char *argv[]) {
     // right now we cannot run for more than config.seq_len steps
     if (steps <= 0 || steps > config.seq_len) { steps = config.seq_len; }
 
-    // read in the tokenizer.bin file
+    // read in the tokenizer .bin file
     char** vocab = (char**)malloc(config.vocab_size * sizeof(char*));
     float* vocab_scores = (float*)malloc(config.vocab_size * sizeof(float));
     unsigned int max_token_length;
     {
-        FILE *file = fopen("tokenizer.bin", "rb");
-        if (!file) { fprintf(stderr, "couldn't load tokenizer.bin\n"); return 1; }
+        FILE *file = fopen(tokenizer, "rb");
+        if (!file) { fprintf(stderr, "couldn't load %s\n", tokenizer); return 1; }
         if (fread(&max_token_length, sizeof(int), 1, file) != 1) { fprintf(stderr, "failed read\n"); return 1; }
         int len;
         for (int i = 0; i < config.vocab_size; i++) {