diff --git a/src/state/queries/post-thread.ts b/src/state/queries/post-thread.ts
index beb50752d0..3f845e3ed3 100644
--- a/src/state/queries/post-thread.ts
+++ b/src/state/queries/post-thread.ts
@@ -330,7 +330,7 @@ function responseToThreadNodes(
 ): ThreadNode {
   if (
     AppBskyFeedDefs.isThreadViewPost(node) &&
-    atp.fastIsType<AppBskyFeedPost.Record>(
+    atp.dangerousIsType<AppBskyFeedPost.Record>(
       node.post.record,
       AppBskyFeedPost.isRecord,
     )
diff --git a/src/state/queries/util.ts b/src/state/queries/util.ts
index 081cb82ecc..e299f013db 100644
--- a/src/state/queries/util.ts
+++ b/src/state/queries/util.ts
@@ -46,7 +46,9 @@ export function didOrHandleUriMatches(
 export function getEmbeddedPost(
   v: unknown,
 ): AppBskyEmbedRecord.ViewRecord | undefined {
-  if (atp.fastIsType<AppBskyEmbedRecord.View>(v, AppBskyEmbedRecord.isView)) {
+  if (
+    atp.dangerousIsType<AppBskyEmbedRecord.View>(v, AppBskyEmbedRecord.isView)
+  ) {
     if (
       AppBskyEmbedRecord.isViewRecord(v.record) &&
       AppBskyFeedPost.isRecord(v.record.value)
@@ -55,7 +57,7 @@ export function getEmbeddedPost(
     }
   }
   if (
-    atp.fastIsType<AppBskyEmbedRecordWithMedia.View>(
+    atp.dangerousIsType<AppBskyEmbedRecordWithMedia.View>(
       v,
       AppBskyEmbedRecordWithMedia.isView,
     )
diff --git a/src/types/atproto/index.ts b/src/types/atproto/index.ts
index 75f78d7b11..18db966ac8 100644
--- a/src/types/atproto/index.ts
+++ b/src/types/atproto/index.ts
@@ -12,11 +12,11 @@ export * as profile from '#/types/atproto/profile'
  * ```ts
  * import * as atp from '#/types/atproto'
  *
- * if (atp.fastIsType<AppBskyFeedPost.Record>(node.post.record, AppBskyFeedPost.isRecord)) {
+ * if (atp.dangerousIsType<AppBskyFeedPost.Record>(node.post.record, AppBskyFeedPost.isRecord)) {
  * }
  * ```
  */
-export function fastIsType<R extends {$type?: string}>(
+export function dangerousIsType<R extends {$type?: string}>(
   record: unknown,
   identity: <V>(v: V) => v is V & {$type: NonNullable<R['$type']>},
 ): record is R {