diff --git a/keyserver/storage/postgres/one_time_keys_table.go b/keyserver/storage/postgres/one_time_keys_table.go
index d8c76b49b..2117efcae 100644
--- a/keyserver/storage/postgres/one_time_keys_table.go
+++ b/keyserver/storage/postgres/one_time_keys_table.go
@@ -53,7 +53,9 @@ const selectKeysSQL = "" +
 	"SELECT concat(algorithm, ':', key_id) as algorithmwithid, key_json FROM keyserver_one_time_keys WHERE user_id=$1 AND device_id=$2 AND concat(algorithm, ':', key_id) = ANY($3);"
 
 const selectKeysCountSQL = "" +
-	"SELECT algorithm, COUNT(key_id) FROM keyserver_one_time_keys WHERE user_id=$1 AND device_id=$2 GROUP BY algorithm"
+	"SELECT algorithm, COUNT(key_id) FROM " +
+	" (SELECT algorithm, key_id FROM keyserver_one_time_keys WHERE user_id = $1 AND device_id = $2 LIMIT 100)" +
+	" x GROUP BY algorithm"
 
 const deleteOneTimeKeySQL = "" +
 	"DELETE FROM keyserver_one_time_keys WHERE user_id = $1 AND device_id = $2 AND algorithm = $3 AND key_id = $4"
diff --git a/keyserver/storage/sqlite3/one_time_keys_table.go b/keyserver/storage/sqlite3/one_time_keys_table.go
index d2c0b7b20..7a923d0e5 100644
--- a/keyserver/storage/sqlite3/one_time_keys_table.go
+++ b/keyserver/storage/sqlite3/one_time_keys_table.go
@@ -52,7 +52,9 @@ const selectKeysSQL = "" +
 	"SELECT key_id, algorithm, key_json FROM keyserver_one_time_keys WHERE user_id=$1 AND device_id=$2"
 
 const selectKeysCountSQL = "" +
-	"SELECT algorithm, COUNT(key_id) FROM keyserver_one_time_keys WHERE user_id=$1 AND device_id=$2 GROUP BY algorithm"
+	"SELECT algorithm, COUNT(key_id) FROM " +
+	" (SELECT algorithm, key_id FROM keyserver_one_time_keys WHERE user_id = $1 AND device_id = $2 LIMIT 100)" +
+	" x GROUP BY algorithm"
 
 const deleteOneTimeKeySQL = "" +
 	"DELETE FROM keyserver_one_time_keys WHERE user_id = $1 AND device_id = $2 AND algorithm = $3 AND key_id = $4"