diff --git a/src/random.ts b/src/random.ts
index a653472f7f8..448cf4f8696 100644
--- a/src/random.ts
+++ b/src/random.ts
@@ -326,7 +326,7 @@ export class Random {
       const randomWordMethod = this.faker.random.arrayElement(wordMethods);
 
       result = randomWordMethod();
-    } while (bannedChars.some((char) => result.includes(char)));
+    } while (!result || bannedChars.some((char) => result.includes(char)));
 
     return this.faker.random.arrayElement(result.split(' '));
   }
diff --git a/test/system.spec.ts b/test/system.spec.ts
index de7d0390dff..26b5730fbdb 100644
--- a/test/system.spec.ts
+++ b/test/system.spec.ts
@@ -268,4 +268,19 @@ describe('system', () => {
       });
     }
   });
+
+  describe('extra tests', () => {
+    describe('commonFileName()', () => {
+      afterEach(() => {
+        faker.locale = 'en';
+      });
+
+      it('#770', () => {
+        faker.seed(5423027051750305);
+        faker.setLocale('sk');
+        faker.system.commonFileName('xml');
+        faker.system.commonFileName('xml');
+      });
+    });
+  });
 });