diff --git a/packages/compiler/src/frontend/lowering/builtins/reflection.ts b/packages/compiler/src/frontend/lowering/builtins/reflection.ts
index ef55fa7e5..2988f9feb 100644
--- a/packages/compiler/src/frontend/lowering/builtins/reflection.ts
+++ b/packages/compiler/src/frontend/lowering/builtins/reflection.ts
@@ -62,6 +62,40 @@ export function lowerReflectCall(
   }
   if (call.questionDotToken) return null;
   const reflectMember = lowerer.stdlibGlobalMember(access, "Reflect");
+  // Reflect.has(target, key) — the `in` operator's presence query over
+  // the target's checked-dynamic view (own and inherited names, proxy
+  // `has` traps included). A primitive target is Node's TypeError
+  // ("Reflect.has called on non-object"), which the presence query
+  // answers false for instead: fenced, never silently divergent.
+  if (
+    reflectMember === "has" &&
+    call.arguments.nodes.length === 2 &&
+    !call.arguments.nodes.some(ts.isSpreadElement)
+  ) {
+    const loc = locOf(call);
+    const target = lowerer.lowerExpr(call.arguments.nodes[0]!);
+    const primitive =
+      isUnitType(target.type) ||
+      ["bool", "f64", "string", "bigint", "symbol"].includes(target.type.kind);
+    if (primitive)
+      lowerer.noLowering(
+        "Reflect.has on a primitive target",
+        call.arguments.nodes[0]!,
+        "Node throws a TypeError for a primitive target; narrow to an object first",
+      );
+    if (!lowerer.dynConvertible(target.type))
+      lowerer.noLowering("Reflect.has on this target", call.arguments.nodes[0]!);
+    return {
+      kind: "libCall",
+      fn: "dyn.hasKeyComputed",
+      args: [
+        lowerer.coerceToExpected(target, DYN),
+        lowerer.lowerExprExpecting(call.arguments.nodes[1]!, DYN),
+      ],
+      type: BOOL,
+      loc,
+    };
+  }
   // Reflect.getOwnPropertyDescriptor and Reflect.defineProperty over
   // checked objects (execa's Promise mixin): the Object operations, with
   // defineProperty answering true. A non-object target throws the Object
diff --git a/packages/compiler/src/frontend/lowering/lower-calls.ts b/packages/compiler/src/frontend/lowering/lower-calls.ts
index 955b57610..fa7afada4 100644
--- a/packages/compiler/src/frontend/lowering/lower-calls.ts
+++ b/packages/compiler/src/frontend/lowering/lower-calls.ts
@@ -7885,6 +7885,10 @@ function lowerObjectStaticCall(
       isUnitType(object.type)
     )
       object = { kind: "dynFrom", value: object, type: DYN, loc: locOf(call) };
+    // A record, array or class instance reflects through its own
+    // checked-dynamic view (own fields and elements, in property order).
+    if (object.type.kind !== "dyn" && lowerer.dynConvertible(object.type))
+      object = lowerer.coerceToExpected(object, DYN);
     if (object.type.kind === "dyn")
       return {
         kind: "libCall",
diff --git a/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/8426-reflect-object-reflections.ts.json b/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/8426-reflect-object-reflections.ts.json
new file mode 100644
index 000000000..4081fc5ef
--- /dev/null
+++ b/packages/compiler/test/ts7/baselines/order-parity/tests/corpus/8426-reflect-object-reflections.ts.json
@@ -0,0 +1,6 @@
+{
+ "order": [
+  "<repo>/tests/corpus/8426-reflect-object-reflections.ts"
+ ],
+ "diags": []
+}
diff --git a/tests/corpus/8426-reflect-object-reflections.ts b/tests/corpus/8426-reflect-object-reflections.ts
new file mode 100644
index 000000000..bae308d81
--- /dev/null
+++ b/tests/corpus/8426-reflect-object-reflections.ts
@@ -0,0 +1,28 @@
+// Reflect.has over the checked-dynamic view, and the Object reflection
+// operations over records, arrays and class instances (own fields and
+// elements in property order). Reflect.has is [[HasProperty]], so inherited
+// names (Array.prototype's, Object.prototype's, a class's methods) answer
+// true; a primitive target is Node's TypeError and stays a lowerer fence
+// (SC2020) rather than a silent `false`.
+class Point {
+  x = 1;
+  y = 2;
+  sum(): number {
+    return this.x + this.y;
+  }
+}
+const record = { a: 1, b: "two" };
+const list = [10, 20];
+const point = new Point();
+console.log(Reflect.has(record, "a"), Reflect.has(record, "z"));
+console.log(Reflect.has(list, "0"), Reflect.has(list, "length"), Reflect.has(list, "9"));
+console.log(Reflect.has(point, "x"), Reflect.has(point, "sum"));
+const key = "b";
+console.log(Reflect.has(record, key), Reflect.has(record, key.toUpperCase()));
+console.log(Reflect.has(record, "toString"), Reflect.has(record, "constructor"));
+console.log(Object.getOwnPropertyNames(record).join(","));
+console.log(Object.getOwnPropertyNames(point).join(","));
+console.log(Object.getOwnPropertyNames(list).length);
+const descriptors = Object.getOwnPropertyDescriptors(record);
+console.log(Object.keys(descriptors).join(","));
+console.log(Object.getOwnPropertySymbols(record).length);
diff --git a/tests/harness/corpus-costs/8426-reflect-object-reflections.ts.json b/tests/harness/corpus-costs/8426-reflect-object-reflections.ts.json
new file mode 100644
index 000000000..a1a93d6be
--- /dev/null
+++ b/tests/harness/corpus-costs/8426-reflect-object-reflections.ts.json
@@ -0,0 +1 @@
+{ "plain": 3121, "san": 5843 }