diff --git a/src/string/trimEnd.ts b/src/string/trimEnd.ts
index 33237a187..d712bfa3f 100644
--- a/src/string/trimEnd.ts
+++ b/src/string/trimEnd.ts
@@ -36,6 +36,7 @@ export function trimEnd(str: string, chars?: string | string[]): string {
       while (endIndex > 0 && chars.includes(str[endIndex - 1])) {
         endIndex--;
       }
+      break;
     }
   }
 
diff --git a/src/string/trimStart.spec.ts b/src/string/trimStart.spec.ts
index df5eca675..db6bc81cd 100644
--- a/src/string/trimStart.spec.ts
+++ b/src/string/trimStart.spec.ts
@@ -65,4 +65,8 @@ describe('trimStart', () => {
   it('should remove leading spaces and other characters when specified in an array', () => {
     expect(trimStart('   hello world', [' ', 'h'])).toEqual('ello world');
   });
+
+  it('should throw an error when chars is a string with multiple characters', () => {
+    expect(() => trimStart('hello', 'ab')).toThrow(`The 'chars' parameter should be a single character string.`);
+  });
 });
diff --git a/src/string/trimStart.ts b/src/string/trimStart.ts
index f25da8e26..6f829501d 100644
--- a/src/string/trimStart.ts
+++ b/src/string/trimStart.ts
@@ -23,6 +23,10 @@ export function trimStart(str: string, chars?: string | string[]): string {
 
   switch (typeof chars) {
     case 'string': {
+      if (chars.length !== 1) {
+        throw new Error(`The 'chars' parameter should be a single character string.`);
+      }
+
       while (startIndex < str.length && str[startIndex] === chars) {
         startIndex++;
       }
@@ -32,6 +36,7 @@ export function trimStart(str: string, chars?: string | string[]): string {
       while (startIndex < str.length && chars.includes(str[startIndex])) {
         startIndex++;
       }
+      break;
     }
   }