diff --git a/common/arg.cpp b/common/arg.cpp
index 2669cacd6c..7673299bd4 100644
--- a/common/arg.cpp
+++ b/common/arg.cpp
@@ -894,6 +894,12 @@ static bool common_params_parse_ex(int argc, char ** argv, common_params_context
     postprocess_cpu_params(params.speculative.draft.cpuparams,       &params.cpuparams);
     postprocess_cpu_params(params.speculative.draft.cpuparams_batch, &params.cpuparams_batch);
 
+    // default the mmproj device to the global device selection if not set explicitly with -mmdev
+    if (params.mmproj_use_gpu && params.mmproj_device == nullptr && !params.devices.empty()) {
+        params.mmproj_device = params.devices.front();
+        params.mmproj_use_gpu = params.mmproj_device != nullptr;
+    }
+
     if (params.prompt_cache_all && (params.interactive || params.interactive_first)) {
         throw std::invalid_argument("error: --prompt-cache-all not supported in interactive mode yet\n");
     }