diff --git a/common/speculative.cpp b/common/speculative.cpp
index 77dfe9535f3..009ede3ad55 100644
--- a/common/speculative.cpp
+++ b/common/speculative.cpp
@@ -2497,6 +2497,7 @@ common_params common_base_params_to_speculative(const common_params & params) {
 
     result.cache_type_k  = params_spec.cache_type_k;
     result.cache_type_v  = params_spec.cache_type_v;
+    result.n_seq_decision = 0; // decision sequences live on the main context only
     result.n_outputs_max = params.n_parallel;
     result.n_outputs_max_per_seq = 1;