diff --git a/lib/hooks/message-hooks.js b/lib/hooks/message-hooks.js
--- a/lib/hooks/message-hooks.js
+++ b/lib/hooks/message-hooks.js
@@ -190,11 +190,11 @@
 
     const keyserverID = extractKeyserverIDFromID(input.threadID);
     const requests = {
-      [keyserverID]: {
+      [keyserverID]: ({
         cursors: {
           [threadID]: beforeMessageID,
         },
-      },
+      }: { [string]: mixed }),
     };
 
     if (input.numMessagesToFetch) {
@@ -226,11 +226,11 @@
 
     const keyserverID = extractKeyserverIDFromID(input.threadID);
     const requests = {
-      [keyserverID]: {
+      [keyserverID]: ({
         cursors: {
           [threadID]: null,
         },
-      },
+      }: { [string]: mixed }),
     };
 
     if (input.numMessagesToFetch) {