diff --git a/frontend/src/pages/AccountReceive.vue b/frontend/src/pages/AccountReceive.vue
index 2a332197d..a05546cc8 100644
--- a/frontend/src/pages/AccountReceive.vue
+++ b/frontend/src/pages/AccountReceive.vue
@@ -37,14 +37,14 @@
               <div class="row justify-start q-col-gutter-md">
                 <base-input
                   v-model.number="startBlockLocal"
-                  @blur="setScanBlocks(startBlockLocal, endBlockLocal)"
+                  @blur="setScanBlocks(startBlockLocal!, endBlockLocal!)"
                   class="col-xs-12 col-6"
                   :label="$t('Receive.start-block')"
                   :rules="isValidStartBlock"
                 />
                 <base-input
                   v-model.number="endBlockLocal"
-                  @blur="setScanBlocks(startBlockLocal, endBlockLocal)"
+                  @blur="setScanBlocks(startBlockLocal!, endBlockLocal!)"
                   class="col-xs-12 col-6"
                   :label="$t('Receive.end-block')"
                   :rules="isValidEndBlock"
@@ -84,7 +84,7 @@
 import { computed, defineComponent, onMounted, ref, watch } from 'vue';
 import { QForm } from 'quasar';
 import { UserAnnouncement, KeyPair, AnnouncementDetail, utils } from '@umbracash/umbra-js';
-import { BigNumber, JsonRpcSigner, computeAddress, isHexString } from 'src/utils/ethers';
+import { BigNumber, computeAddress, isHexString } from 'src/utils/ethers';
 import useSettingsStore from 'src/store/settings';
 import useWalletStore from 'src/store/wallet';
 import useWallet from 'src/store/wallet';
@@ -180,11 +180,9 @@ function useScan() {
     const overrides = { startBlock: startBlockLocal.value, endBlock: endBlockLocal.value };
     let allAnnouncements: AnnouncementDetail[] = [];
     try {
-      allAnnouncements = await umbra.value.fetchSomeAnnouncements(
-        signer.value as JsonRpcSigner,
-        userWalletAddress.value as string,
-        overrides
-      );
+      if (!signer.value) throw new Error('signer is undefined');
+      if (!userWalletAddress.value) throw new Error('userWalletAddress is undefined');
+      allAnnouncements = await umbra.value.fetchSomeAnnouncements(signer.value, userWalletAddress.value, overrides);
     } catch (e) {
       scanStatus.value = 'waiting'; // reset to the default state because we were unable to fetch announcements
       throw e;