diff --git a/common/speculative.cpp b/common/speculative.cpp
index aa0d0ed86..628ded45c 100644
--- a/common/speculative.cpp
+++ b/common/speculative.cpp
@@ -58,10 +58,10 @@ static bool common_speculative_are_compatible(
     const llama_vocab * vocab_tgt = llama_model_get_vocab(model_tgt);
     const llama_vocab * vocab_dft = llama_model_get_vocab(model_dft);
 
-    const bool vocab_type_tgt = llama_vocab_type(vocab_tgt);
+    const auto vocab_type_tgt = llama_vocab_type(vocab_tgt);
     LOG_DBG("%s: vocab_type tgt: %d\n", __func__, vocab_type_tgt);
 
-    const bool vocab_type_dft = llama_vocab_type(vocab_dft);
+    const auto vocab_type_dft = llama_vocab_type(vocab_dft);
     LOG_DBG("%s: vocab_type dft: %d\n", __func__, vocab_type_dft);
 
     if (vocab_type_tgt != vocab_type_dft) {