diff --git a/src/functions/__tests__/casing.test.ts b/src/functions/__tests__/casing.test.ts
index d5fc5596e..8da9fa887 100644
--- a/src/functions/__tests__/casing.test.ts
+++ b/src/functions/__tests__/casing.test.ts
@@ -265,6 +265,13 @@ describe('casing', () => {
       );
     });
 
+    test.each(Object.values(CasingType))('properly detects leading char for %s casing', casing => {
+      expect(runCasing('/', casing, true, { allowLeading: true, char: '/' })).toBeUndefined();
+      expect(runCasing('//', casing, true, { allowLeading: true, char: '/' })).toEqual([
+        { message: `must be ${casing} case` },
+      ]);
+    });
+
     test('allows advanced scenarios', () => {
       expect(runCasing('X-MyAmazing-Header', CasingType.pascal, true, { char: '-' })).toBeUndefined();
       expect(
diff --git a/src/functions/casing.ts b/src/functions/casing.ts
index fffe480ae..fb85400ed 100644
--- a/src/functions/casing.ts
+++ b/src/functions/casing.ts
@@ -36,6 +36,15 @@ export const casing: IFunction<ICasingOptions> = (targetVal, opts) => {
     return;
   }
 
+  if (
+    targetVal.length === 1 &&
+    opts.separator !== void 0 &&
+    opts.separator.allowLeading === true &&
+    targetVal === opts.separator.char
+  ) {
+    return;
+  }
+
   const casingValidator = buildFrom(CASES[opts.type], opts);
 
   if (casingValidator.test(targetVal)) {