diff --git a/packages/shared/src/issue-thread-interactions.test.ts b/packages/shared/src/issue-thread-interactions.test.ts
index 630d0c9da95..66ca57ea3a5 100644
--- a/packages/shared/src/issue-thread-interactions.test.ts
+++ b/packages/shared/src/issue-thread-interactions.test.ts
@@ -209,6 +209,15 @@ describe("issue thread interaction schemas", () => {
       },
     })).toThrow("defaultSelectedOptionIds must reference existing option ids");
 
+    expect(() => createIssueThreadInteractionSchema.parse({
+      ...base,
+      payload: {
+        ...base.payload,
+        defaultSelectedOptionIds: ["item-1"],
+        minSelected: 2,
+      },
+    })).toThrow("defaultSelectedOptionIds must satisfy minSelected");
+
     expect(() => createIssueThreadInteractionSchema.parse({
       ...base,
       payload: {
diff --git a/packages/shared/src/validators/issue.ts b/packages/shared/src/validators/issue.ts
index fa8c8a362db..7d7454c494d 100644
--- a/packages/shared/src/validators/issue.ts
+++ b/packages/shared/src/validators/issue.ts
@@ -795,6 +795,13 @@ export const requestCheckboxConfirmationPayloadSchema = z.object({
       path: ["minSelected"],
     });
   }
+  if (value.defaultSelectedOptionIds.length < value.minSelected) {
+    ctx.addIssue({
+      code: z.ZodIssueCode.custom,
+      message: "defaultSelectedOptionIds must satisfy minSelected",
+      path: ["defaultSelectedOptionIds"],
+    });
+  }
   if (maxSelected != null) {
     if (maxSelected < value.minSelected) {
       ctx.addIssue({
diff --git a/server/src/__tests__/issue-thread-interactions-service.test.ts b/server/src/__tests__/issue-thread-interactions-service.test.ts
index f4828a6f493..845eb42ffba 100644
--- a/server/src/__tests__/issue-thread-interactions-service.test.ts
+++ b/server/src/__tests__/issue-thread-interactions-service.test.ts
@@ -820,6 +820,7 @@ describeEmbeddedPostgres("issueThreadInteractionService", () => {
           { id: "two", label: "Two" },
           { id: "three", label: "Three" },
         ],
+        defaultSelectedOptionIds: ["one"],
         minSelected: 1,
         maxSelected: 2,
       },
diff --git a/ui/src/components/IssueThreadInteractionCard.test.tsx b/ui/src/components/IssueThreadInteractionCard.test.tsx
index 9687ae8b61f..f4791a1ae9d 100644
--- a/ui/src/components/IssueThreadInteractionCard.test.tsx
+++ b/ui/src/components/IssueThreadInteractionCard.test.tsx
@@ -442,6 +442,11 @@ describe("IssueThreadInteractionCard", () => {
       .filter((box) => box.getAttribute("aria-checked") === "false");
     expect(stillUnchecked.length).toBeGreaterThan(0);
     expect(stillUnchecked.every((box) => box.hasAttribute("disabled"))).toBe(true);
+
+    const selectAllButton = Array.from(host.querySelectorAll("button")).find((button) =>
+      button.textContent?.includes("Select all"),
+    );
+    expect(selectAllButton?.hasAttribute("disabled")).toBe(true);
   });
 
   it("summarizes large accepted selections by count and bounds the chips", () => {
diff --git a/ui/src/components/IssueThreadInteractionCard.tsx b/ui/src/components/IssueThreadInteractionCard.tsx
index 13c7303c08e..a26ac400a4c 100644
--- a/ui/src/components/IssueThreadInteractionCard.tsx
+++ b/ui/src/components/IssueThreadInteractionCard.tsx
@@ -1611,7 +1611,7 @@ function RequestCheckboxConfirmationCard({
             <Button
               size="sm"
               variant="ghost"
-              disabled={working !== null || selectedCount === totalOptions}
+              disabled={working !== null || selectedCount === totalOptions || (maxSelected != null && selectedCount >= maxSelected)}
               onClick={handleSelectAll}
             >
               Select all