diff --git a/llama.cpp b/llama.cpp
index 82b7638ae..03c73ee7b 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -2235,15 +2235,32 @@ static void llm_load_vocab(
     if (vocab.type == LLAMA_VOCAB_TYPE_SPM) {
         vocab.linefeed_id = llama_byte_to_token(vocab, '\n');
     } else {
-        vocab.linefeed_id = llama_tokenize_internal(vocab, "\u010A", false)[0];
+        const std::vector<int> ids = llama_tokenize_internal(vocab, "\u010A", false);
+        GGML_ASSERT(ids.size() == 1 && "model vocab missing newline token");
+        vocab.linefeed_id = ids[0];
     }
 
     // special tokens
-    GGUF_GET_KEY(ctx, vocab.special_bos_id, gguf_get_val_u32, GGUF_TYPE_UINT32, false, kv(LLM_KV_TOKENIZER_BOS_ID));
-    GGUF_GET_KEY(ctx, vocab.special_eos_id, gguf_get_val_u32, GGUF_TYPE_UINT32, false, kv(LLM_KV_TOKENIZER_EOS_ID));
-    GGUF_GET_KEY(ctx, vocab.special_unk_id, gguf_get_val_u32, GGUF_TYPE_UINT32, false, kv(LLM_KV_TOKENIZER_UNK_ID));
-    GGUF_GET_KEY(ctx, vocab.special_sep_id, gguf_get_val_u32, GGUF_TYPE_UINT32, false, kv(LLM_KV_TOKENIZER_SEP_ID));
-    GGUF_GET_KEY(ctx, vocab.special_pad_id, gguf_get_val_u32, GGUF_TYPE_UINT32, false, kv(LLM_KV_TOKENIZER_PAD_ID));
+    {
+        const std::vector<std::tuple<enum llm_kv, int32_t *>> special_token_types = {
+            { LLM_KV_TOKENIZER_BOS_ID, &vocab.special_bos_id },
+            { LLM_KV_TOKENIZER_EOS_ID, &vocab.special_eos_id },
+            { LLM_KV_TOKENIZER_UNK_ID, &vocab.special_unk_id },
+            { LLM_KV_TOKENIZER_SEP_ID, &vocab.special_sep_id },
+            { LLM_KV_TOKENIZER_PAD_ID, &vocab.special_pad_id },
+        };
+        for (auto & it : special_token_types ) {
+            int32_t id = -1;
+            const std::string kstr = kv(std::get<0>(it));
+
+            GGUF_GET_KEY(ctx, id, gguf_get_val_u32, GGUF_TYPE_UINT32, false, kstr);
+            if (id != -1 && (id < 0 || size_t(id) >= vocab.id_to_token.size())) {
+                LLAMA_LOG_WARN("%s: bad special token value %d for key '%s' -- ignoring\n", __func__, id, kstr.c_str());
+                continue;
+            }
+            *(std::get<1>(it)) = id;
+        }
+    }
 
     // build special tokens cache
     {
@@ -6084,11 +6101,10 @@ static uint8_t llama_token_to_byte(const llama_vocab& vocab, llama_token id) {
 }
 
 static llama_token llama_byte_to_token(const llama_vocab & vocab, uint8_t ch) {
+    const char * hex = "0123456789ABCDEF";
     switch (llama_vocab_get_type(vocab)) {
     case LLAMA_VOCAB_TYPE_SPM: {
-        char buf[7];
-        int result = snprintf(buf, sizeof(buf), "<0x%02X>", ch);
-        GGML_ASSERT(0 <= result && result < 7);
+        const char buf[7] = { '<', '0', 'x', hex[ch >> 4], hex[ch & 15], '>', 0 };
         return vocab.token_to_id.at(buf);
     }
     case LLAMA_VOCAB_TYPE_BPE: {