diff --git a/packages/insomnia-app/app/ui/redux/modules/global.tsx b/packages/insomnia-app/app/ui/redux/modules/global.tsx
index 98abde49d..6d4c1cd1f 100644
--- a/packages/insomnia-app/app/ui/redux/modules/global.tsx
+++ b/packages/insomnia-app/app/ui/redux/modules/global.tsx
@@ -43,6 +43,7 @@ import { Settings } from '../../../models/settings';
 import { GrpcRequest } from '../../../models/grpc-request';
 import { Request } from '../../../models/request';
 import { Environment } from '../../../models/environment';
+import { unreachableCase } from 'ts-assert-unreachable';
 
 export const LOCALSTORAGE_PREFIX = 'insomnia::meta';
 const LOGIN_STATE_CHANGE = 'global/login-state-change';
@@ -489,24 +490,27 @@ export const importUri = (
 };
 
 function showSelectExportTypeModal(onCancel: () => void, onDone: (selectedFormat: SelectedFormat) => void) {
+  const options = [
+    {
+      name: 'Insomnia v4 (JSON)',
+      value: VALUE_JSON,
+    },
+    {
+      name: 'Insomnia v4 (YAML)',
+      value: VALUE_YAML,
+    },
+    {
+      name: 'HAR – HTTP Archive Format',
+      value: VALUE_HAR,
+    },
+  ];
   const lastFormat = window.localStorage.getItem('insomnia.lastExportFormat');
+  const defaultValue = options.map(({ value }) => value).includes(lastFormat) ? lastFormat : VALUE_JSON;
+
   showModal(SelectModal, {
     title: 'Select Export Type',
-    value: lastFormat,
-    options: [
-      {
-        name: 'Insomnia v4 (JSON)',
-        value: VALUE_JSON,
-      },
-      {
-        name: 'Insomnia v4 (YAML)',
-        value: VALUE_YAML,
-      },
-      {
-        name: 'HAR – HTTP Archive Format',
-        value: VALUE_HAR,
-      },
-    ],
+    value: defaultValue,
+    options,
     message: 'Which format would you like to export as?',
     onCancel,
     onDone: (selectedFormat: SelectedFormat) => {
@@ -599,6 +603,9 @@ export const exportWorkspacesToFile = (workspaceId: string | undefined = undefin
               'json',
             );
             break;
+
+          default:
+            unreachableCase(`selected export format "${selectedFormat}" is invalid`);
         }
       } catch (err) {
         showError({
@@ -698,6 +705,9 @@ export const exportRequestsToFile = (requestIds: string[]) => async dispatch =>
             'json',
           );
           break;
+
+          default:
+            unreachableCase(`selected export format "${selectedFormat}" is invalid`);
         }
       } catch (err) {
         showError({
diff --git a/packages/insomnia-app/package-lock.json b/packages/insomnia-app/package-lock.json
index 6dc750ecb..1ac94b2c7 100644
--- a/packages/insomnia-app/package-lock.json
+++ b/packages/insomnia-app/package-lock.json
@@ -24462,6 +24462,14 @@
 				"utf8-byte-length": "^1.0.1"
 			}
 		},
+		"ts-assert-unreachable": {
+			"version": "0.0.9",
+			"resolved": "https://registry.npmjs.org/ts-assert-unreachable/-/ts-assert-unreachable-0.0.9.tgz",
+			"integrity": "sha512-8tpQLahyZSNTSxKS8QPIO0AAxF8VB02tLPNqcMF638gNDOrhr8uGx9SFP1C/Vtbib2Xc/u12hiXnwmqD7pn+2A==",
+			"requires": {
+				"ts-tiny-invariant": "0.0.3"
+			}
+		},
 		"ts-dedent": {
 			"version": "1.1.1",
 			"resolved": "https://registry.npmjs.org/ts-dedent/-/ts-dedent-1.1.1.tgz",
@@ -24587,6 +24595,11 @@
 			"integrity": "sha512-csd+vJOb/gkzvcCHgTGSChYpy5f1/XKNsmvBGO4JXS+z1v2HobugDz4s1IeFXM3wZB44uczs+eazB5Q/ccdhQw==",
 			"dev": true
 		},
+		"ts-tiny-invariant": {
+			"version": "0.0.3",
+			"resolved": "https://registry.npmjs.org/ts-tiny-invariant/-/ts-tiny-invariant-0.0.3.tgz",
+			"integrity": "sha512-EiaBUsUta7PPzVKpvZurcSDgaSkymxwiUc2rhX6Wu30bws2maipT6ihbEY072dU9lz6/FoFWEc6psXdlo0xqtg=="
+		},
 		"tsconfig-paths": {
 			"version": "3.9.0",
 			"resolved": "https://registry.npmjs.org/tsconfig-paths/-/tsconfig-paths-3.9.0.tgz",
diff --git a/packages/insomnia-app/package.json b/packages/insomnia-app/package.json
index ececd49ef..ce045a986 100644
--- a/packages/insomnia-app/package.json
+++ b/packages/insomnia-app/package.json
@@ -154,6 +154,7 @@
     "styled-components": "^4.4.1",
     "swagger-ui-react": "^3.24.3",
     "tough-cookie": "^2.3.1",
+    "ts-assert-unreachable": "^0.0.9",
     "url-join": "^4.0.1",
     "uuid": "^3.0.0",
     "vkbeautify": "^0.99.1",