diff --git a/src/DeviceListener.ts b/src/DeviceListener.ts
index f1b22c2c71..3281c43267 100644
--- a/src/DeviceListener.ts
+++ b/src/DeviceListener.ts
@@ -251,7 +251,8 @@ export default class DeviceListener {
         if (!this.running) return; // we have been stopped
         const cli = MatrixClientPeg.get();
 
-        if (!(await cli.doesServerSupportUnstableFeature("org.matrix.e2e_cross_signing"))) return;
+        // cross-signing support was added to Matrix in MSC1756, which landed in spec v1.1
+        if (!(await cli.isVersionSupported("v1.1"))) return;
 
         if (!cli.isCryptoEnabled()) return;
         // don't recheck until the initial sync is complete: lots of account data events will fire
diff --git a/src/rageshake/submit-rageshake.ts b/src/rageshake/submit-rageshake.ts
index f1926b6ca1..9027e2870f 100644
--- a/src/rageshake/submit-rageshake.ts
+++ b/src/rageshake/submit-rageshake.ts
@@ -95,10 +95,6 @@ async function collectBugReport(opts: IOpts = {}, gzipLogs = true): Promise<Form
             const secretStorage = client.crypto.secretStorage;
 
             body.append("cross_signing_ready", String(await client.isCrossSigningReady()));
-            body.append(
-                "cross_signing_supported_by_hs",
-                String(await client.doesServerSupportUnstableFeature("org.matrix.e2e_cross_signing")),
-            );
             body.append("cross_signing_key", crossSigning.getId() ?? "n/a");
             body.append(
                 "cross_signing_privkey_in_secret_storage",
diff --git a/src/sentry.ts b/src/sentry.ts
index 24ef30a048..61098bf59d 100644
--- a/src/sentry.ts
+++ b/src/sentry.ts
@@ -132,9 +132,6 @@ async function getCryptoContext(client: MatrixClient): Promise<CryptoContext> {
     return {
         device_keys: keys.join(", "),
         cross_signing_ready: String(await client.isCrossSigningReady()),
-        cross_signing_supported_by_hs: String(
-            await client.doesServerSupportUnstableFeature("org.matrix.e2e_cross_signing"),
-        ),
         cross_signing_key: crossSigning.getId()!,
         cross_signing_privkey_in_secret_storage: String(!!(await crossSigning.isStoredInSecretStorage(secretStorage))),
         cross_signing_master_privkey_cached: String(!!(pkCache && (await pkCache.getCrossSigningKeyCache?.("master")))),
diff --git a/test/DeviceListener-test.ts b/test/DeviceListener-test.ts
index dea4ab1987..c0470200d7 100644
--- a/test/DeviceListener-test.ts
+++ b/test/DeviceListener-test.ts
@@ -80,7 +80,7 @@ describe("DeviceListener", () => {
             getUserId: jest.fn().mockReturnValue(userId),
             getKeyBackupVersion: jest.fn().mockResolvedValue(undefined),
             getRooms: jest.fn().mockReturnValue([]),
-            doesServerSupportUnstableFeature: jest.fn().mockResolvedValue(true),
+            isVersionSupported: jest.fn().mockResolvedValue(true),
             isCrossSigningReady: jest.fn().mockResolvedValue(true),
             isSecretStorageReady: jest.fn().mockResolvedValue(true),
             isCryptoEnabled: jest.fn().mockReturnValue(true),
@@ -234,9 +234,10 @@ describe("DeviceListener", () => {
 
     describe("recheck", () => {
         it("does nothing when cross signing feature is not supported", async () => {
-            mockClient!.doesServerSupportUnstableFeature.mockResolvedValue(false);
+            mockClient!.isVersionSupported.mockResolvedValue(false);
             await createAndStart();
 
+            expect(mockClient!.isVersionSupported).toHaveBeenCalledWith("v1.1");
             expect(mockClient!.isCrossSigningReady).not.toHaveBeenCalled();
         });
         it("does nothing when crypto is not enabled", async () => {