diff --git a/packages/core/test/form.test.ts b/packages/core/test/form.test.ts
index 7ea351df3a6..e032cf6c714 100644
--- a/packages/core/test/form.test.ts
+++ b/packages/core/test/form.test.ts
@@ -92,6 +92,79 @@ describe("Form", () => {
     }),
   )
 
+  it.effect("requires every when condition to match and treats empty when as active", () =>
+    Effect.gen(function* () {
+      const service = yield* Form.Service
+      const created = yield* service.create({
+        sessionID: "global",
+        mode: "form",
+        fields: [
+          { key: "a", type: "boolean" },
+          { key: "b", type: "boolean" },
+          {
+            key: "x",
+            type: "string",
+            required: true,
+            when: [
+              { key: "a", op: "eq", value: true },
+              { key: "b", op: "eq", value: true },
+            ],
+          },
+          { key: "z", type: "string", required: true, when: [] },
+        ],
+      })
+
+      const missingX = yield* service.reply({ id: created.id, answer: { a: true, b: true, z: "ok" } }).pipe(Effect.flip)
+      expect(missingX).toEqual(new Form.InvalidAnswerError({ id: created.id, message: "Missing required form field: x" }))
+
+      const inactiveX = yield* service
+        .reply({ id: created.id, answer: { a: true, b: false, x: "nope", z: "ok" } })
+        .pipe(Effect.flip)
+      expect(inactiveX).toEqual(new Form.InvalidAnswerError({ id: created.id, message: "Form field is not active: x" }))
+
+      const missingZ = yield* service.reply({ id: created.id, answer: { a: true, b: false } }).pipe(Effect.flip)
+      expect(missingZ).toEqual(new Form.InvalidAnswerError({ id: created.id, message: "Missing required form field: z" }))
+
+      yield* service.reply({ id: created.id, answer: { a: true, b: false, z: "ok" } })
+      expect(yield* service.state(created.id)).toEqual({ status: "answered", answer: { a: true, b: false, z: "ok" } })
+    }),
+  )
+
+  it.effect("evaluates neq against multiselect answers as non-inclusion", () =>
+    Effect.gen(function* () {
+      const service = yield* Form.Service
+      const options = [
+        { value: "go", label: "Go" },
+        { value: "ts", label: "TypeScript" },
+      ]
+      const created = yield* service.create({
+        sessionID: "global",
+        mode: "form",
+        fields: [
+          { key: "langs", type: "multiselect", options },
+          { key: "note", type: "string", required: true, when: [{ key: "langs", op: "neq", value: "go" }] },
+        ],
+      })
+
+      const missing = yield* service.reply({ id: created.id, answer: { langs: ["ts"] } }).pipe(Effect.flip)
+      expect(missing).toEqual(
+        new Form.InvalidAnswerError({ id: created.id, message: "Missing required form field: note" }),
+      )
+
+      // an answered-but-empty multiselect also satisfies neq
+      const missingEmpty = yield* service.reply({ id: created.id, answer: { langs: [] } }).pipe(Effect.flip)
+      expect(missingEmpty).toEqual(
+        new Form.InvalidAnswerError({ id: created.id, message: "Missing required form field: note" }),
+      )
+
+      const inactive = yield* service.reply({ id: created.id, answer: { langs: ["go"], note: "x" } }).pipe(Effect.flip)
+      expect(inactive).toEqual(new Form.InvalidAnswerError({ id: created.id, message: "Form field is not active: note" }))
+
+      yield* service.reply({ id: created.id, answer: { langs: ["go"] } })
+      expect(yield* service.state(created.id)).toEqual({ status: "answered", answer: { langs: ["go"] } })
+    }),
+  )
+
   it.effect("treats unanswered when references as false and cascades inactivity", () =>
     Effect.gen(function* () {
       const service = yield* Form.Service