gistfile1.txt

diff --git a/src/core/interp.c b/src/core/interp.c
index 7cea172..efe163e 100644
--- a/src/core/interp.c
+++ b/src/core/interp.c
@@ -4370,16 +4370,18 @@ void MVM_interp_run(MVMThreadContext *tc, void (*initial_invoke)(MVMThreadContex
                     GET_REG(cur_op, 4).o, GET_REG(cur_op, 6).o);
                 cur_op += 8;
                 goto NEXT;
-            OP(sp_log):
-                if (tc->cur_frame->spesh_log_idx >= 0) {
+            OP(sp_log): {
+                MVMint32 log_idx = tc->cur_frame->spesh_log_idx;
+                if (log_idx >= 0 && log_idx < MVM_SPESH_LOG_RUNS) {
                     MVM_ASSIGN_REF(tc, &(tc->cur_frame->static_info->common.header),
                         tc->cur_frame->spesh_log_slots[
-                            GET_UI16(cur_op, 2) * MVM_SPESH_LOG_RUNS + tc->cur_frame->spesh_log_idx
+                            GET_UI16(cur_op, 2) * MVM_SPESH_LOG_RUNS + log_idx
                         ],
                         GET_REG(cur_op, 0).o);
                 }
                 cur_op += 4;
                 goto NEXT;
+            }
             OP(sp_osrfinalize): {
                 MVMSpeshCandidate *cand = tc->cur_frame->spesh_cand;
                 if (cand) {