diff --git a/common/speculative.cpp b/common/speculative.cpp
index 349d23dcd201..821c30b36d46 100644
--- a/common/speculative.cpp
+++ b/common/speculative.cpp
@@ -1288,6 +1288,15 @@ bool common_speculative_is_compat(llama_context * ctx_tgt) {
 common_speculative * common_speculative_init(
         common_params_speculative & params,
         llama_context             * ctx_tgt) {
+    // Defensive: if speculative was disabled upstream (e.g. server disables it when mmproj
+    // is loaded), bail out before any impl construction. Without this guard, a caller that
+    // sets params.type=NONE but leaves params.mparams_dft.path (set via --mtp-head/--model-draft)
+    // would still trigger the DRAFT config below with ctx_dft=nullptr, crashing in the
+    // common_speculative_state_draft ctor at llama_n_batch(ctx_dft).
+    if (params.type == COMMON_SPECULATIVE_TYPE_NONE) {
+        return nullptr;
+    }
+
     llama_context * ctx_dft = nullptr;
     // Gemma4 MTP loads the assistant into the target model (llama_model_load_mtp_from_file); no second context.
     if (params.model_dft && params.type != COMMON_SPECULATIVE_TYPE_MTP) {
diff --git a/tools/server/server-context.cpp b/tools/server/server-context.cpp
index fea3ed875026..d49e712b498c 100644
--- a/tools/server/server-context.cpp
+++ b/tools/server/server-context.cpp
@@ -735,6 +735,11 @@ struct server_context_impl {
 
             if (params_base.speculative.type != COMMON_SPECULATIVE_TYPE_NONE) {
                 params_base.speculative.type =  COMMON_SPECULATIVE_TYPE_NONE;
+                // Also clear the draft model path so common_speculative_init does not
+                // observe an orphan has_draft=true with type=NONE (would build a DRAFT
+                // config and crash on ctx_dft=nullptr). See common/speculative.cpp init.
+                params_base.speculative.mparams_dft.path.clear();
+                params_base.speculative.model_dft = nullptr;
                 SRV_WRN("%s\n", "speculative decoding is not supported by multimodal, it will be disabled");
             }
         }