diff --git a/src/types/api.ts b/src/types/api.ts
index 11000e5e..1a6193c7 100644
--- a/src/types/api.ts
+++ b/src/types/api.ts
@@ -186,13 +186,6 @@ export interface CaseInfo {
     path: string;
     /** Directory INSIDE the container (defaults to `path` when unset). */
     containerWorkdir?: string;
-    /**
-     * False = an ADOPTED container the user built and runs. Only those may back
-     * several cases at once (classifyAdoptContainerConflict), so this is what lets
-     * the UI offer "duplicate for another directory" on exactly the right cases —
-     * an owned container's lifecycle belongs to its one case.
-     */
-    owned?: boolean;
     network?: string;
     /**
      * CLIs available INSIDE the container. A container case runs its agents in
@@ -210,6 +203,10 @@ export interface CaseInfo {
      * first session: the container is created on demand by the launch chain, so treating
      * "not found" as a fault there hid every agent mode behind an error telling the user
      * to start a container Codeman was about to create itself.
+     *
+     * It also gates the Add Case panel's "copy an existing case" picker: only an ADOPTED
+     * container may back several cases at once (`classifyAdoptContainerConflict`), since an
+     * owned container's lifecycle belongs to its one case.
      */
     owned?: boolean;
   };
diff --git a/src/web/routes/case-routes.ts b/src/web/routes/case-routes.ts
index 492b52a3..643283e9 100644
--- a/src/web/routes/case-routes.ts
+++ b/src/web/routes/case-routes.ts
@@ -329,7 +329,6 @@ export function registerCaseRoutes(app: FastifyInstance, ctx: EventPort & Config
           image: host.image,
           path: dockerCase.hostWorkspacePath,
           containerWorkdir: dockerCase.containerWorkdir ?? dockerCase.hostWorkspacePath,
-          owned: dockerCase.owned !== false,
           network: host.network ?? 'bridge',
           ...(dockerCase.availableModes ? { availableModes: dockerCase.availableModes } : {}),
           ...(dockerCase.owned === false ? { owned: false } : {}),
@@ -1610,8 +1609,8 @@ export function registerCaseRoutes(app: FastifyInstance, ctx: EventPort & Config
           image: host.image,
           path: dockerCase.hostWorkspacePath,
           containerWorkdir: dockerCase.containerWorkdir ?? dockerCase.hostWorkspacePath,
-          owned: dockerCase.owned !== false,
           network: host.network ?? 'bridge',
+          ...(dockerCase.owned === false ? { owned: false } : {}),
         },
       };
     }
diff --git a/test/docker-adopt-duplicate.test.ts b/test/docker-adopt-duplicate.test.ts
index 10bb90f2..e9cfd77c 100644
--- a/test/docker-adopt-duplicate.test.ts
+++ b/test/docker-adopt-duplicate.test.ts
@@ -27,13 +27,16 @@ describe('the API exposes what the picker needs', () => {
   it('reports whether the container is owned, on EVERY case-shaped response', () => {
     // Two sites build a docker CaseInfo (the list and the single-case lookup);
     // filling only one leaves the picker blind depending on which the UI read.
-    expect(routes.match(/owned: dockerCase\.owned !== false,/g) ?? []).toHaveLength(2);
+    expect(routes.match(/\.\.\.\(dockerCase\.owned === false \? \{ owned: false \} : \{\}\),/g) ?? []).toHaveLength(2);
   });
 
   it('treats an ABSENT owned flag as owned, so legacy cases are not offered', () => {
-    // `owned` is optional and predates this field; truthiness would read a legacy
-    // case as adopted and offer a duplicate the server then refuses.
-    expect(routes).toContain('dockerCase.owned !== false');
+    // `owned` is optional and predates this field; the wire carries it ONLY when
+    // false (absent = owned, the shape master already used), so the picker must
+    // test `=== false` rather than truthiness, or a legacy case would read as
+    // adopted and be offered a duplicate the server then refuses.
+    expect(routes).toContain('...(dockerCase.owned === false ? { owned: false } : {}),');
+    expect(routes).not.toContain('owned: dockerCase.owned !== false');
   });
 });