diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index 010c4c6e3c..707adf7631 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -1088,6 +1088,8 @@ void probe_write(CPUArchState *env, target_ulong addr, int size, int mmu_idx,
     CPUTLBEntry *entry = tlb_entry(env, mmu_idx, addr);
     target_ulong tlb_addr = tlb_addr_write(entry);
 
+    g_assert(-(addr | TARGET_PAGE_MASK) >= size);
+
     if (unlikely(!tlb_hit(tlb_addr, addr))) {
         if (!VICTIM_TLB_HIT(addr_write, addr)) {
             tlb_fill(env_cpu(env), addr, size, MMU_DATA_STORE,
diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index 86e6827201..625c33f893 100644
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -191,6 +191,8 @@ static inline int handle_cpu_signal(uintptr_t pc, siginfo_t *info,
 void probe_write(CPUArchState *env, target_ulong addr, int size, int mmu_idx,
                  uintptr_t retaddr)
 {
+    g_assert(-(addr | TARGET_PAGE_MASK) >= size);
+
     if (!guest_addr_valid(addr) ||
         page_check_range(addr, size, PAGE_WRITE) < 0) {
         CPUState *cpu = env_cpu(env);