diff --git a/src/silver/ops/coercion.h b/src/silver/ops/coercion.h
index 8b09864..5aea603 100644
--- a/src/silver/ops/coercion.h
+++ b/src/silver/ops/coercion.h
@@ -462,15 +462,17 @@ static inline ant_value_t sv_op_with_put_var(
       if (sv_with_binding_is_unscopable(js, frame->with_obj, a, &out, &abrupt)) goto fallback;
       if (abrupt) return out;
       ant_value_t key = js_mkstr(js, a->str, a->len);
-      js_setprop(js, frame->with_obj, key, val);
+      ant_value_t set_result = js_setprop(js, frame->with_obj, key, val);
+      if (is_err(set_result)) return set_result;
       return js_mkundef();
     }
   }
 
 fallback:
-  if (fb_kind == WITH_FB_GLOBAL) 
-    setprop_interned(js, js->global, a->str, a->len, val);
-  else sv_with_fallback_put(vm, js, frame, fb_kind, fb_idx, val);
+  if (fb_kind == WITH_FB_GLOBAL) {
+    ant_value_t set_result = setprop_interned(js, js->global, a->str, a->len, val);
+    if (is_err(set_result)) return set_result;
+  } else sv_with_fallback_put(vm, js, frame, fb_kind, fb_idx, val);
   return js_mkundef();
 }
 
diff --git a/tests/test_with_proxy_write_delete.cjs b/tests/test_with_proxy_write_delete.cjs
index d9c8436..67166b0 100644
--- a/tests/test_with_proxy_write_delete.cjs
+++ b/tests/test_with_proxy_write_delete.cjs
@@ -64,4 +64,44 @@ try {
 
 assert(propagated, "proxy with delete should propagate thrown delete errors");
 
+const throwingSetProxy = new Proxy({}, {
+  has(_target, key) {
+    return key === "x";
+  },
+  set() {
+    throw new Error("set boom");
+  },
+});
+
+propagated = false;
+try {
+  with (throwingSetProxy) {
+    x = 3;
+  }
+} catch (e) {
+  propagated = e.message === "set boom";
+}
+
+assert(propagated, "proxy with assignment should propagate thrown set errors");
+
+Object.defineProperty(globalThis, "withGlobalSetterThrow", {
+  configurable: true,
+  set() {
+    throw new Error("global setter boom");
+  },
+});
+
+propagated = false;
+try {
+  with ({}) {
+    withGlobalSetterThrow = 1;
+  }
+} catch (e) {
+  propagated = e.message === "global setter boom";
+} finally {
+  delete globalThis.withGlobalSetterThrow;
+}
+
+assert(propagated, "with global fallback assignment should propagate thrown setters");
+
 console.log("OK");