diff --git a/src/function/debounce.spec.ts b/src/function/debounce.spec.ts
index a7198c5..9c691e2 100644
--- a/src/function/debounce.spec.ts
+++ b/src/function/debounce.spec.ts
@@ -45,7 +45,7 @@ describe('Debounce Function', () => {
         const executedIn = new Date().getTime() - started;
 
         expect(foo).toBe(1);
-        expect(executedIn).toBeGreaterThan(49);
+        expect(executedIn).toBeGreaterThan(48);
         expect(executedIn).toBeLessThan(60);
 
         done();
diff --git a/src/function/proto/debounce.spec.ts b/src/function/proto/debounce.spec.ts
index d95f955..f8798e7 100644
--- a/src/function/proto/debounce.spec.ts
+++ b/src/function/proto/debounce.spec.ts
@@ -31,7 +31,7 @@ describe('Debounce Proto Function', () => {
     foo.debounce(50, bar, 0, 0)
       .then(() => {
         const sequence = new Date().getTime() - startedAt;
-        expect(sequence).toBeGreaterThan(49);
+        expect(sequence).toBeGreaterThan(48);
         expect(sequence).toBeLessThan(60);
 
         expect(bar.x).toBe(8);
diff --git a/src/open-promise.spec.ts b/src/open-promise.spec.ts
index 3dca757..570a280 100644
--- a/src/open-promise.spec.ts
+++ b/src/open-promise.spec.ts
@@ -13,7 +13,7 @@ describe('Open Promise Class', () => {
     const startedAt = new Date().getTime();
 
     op.promise.then(value => {
-      expect(new Date().getTime() - startedAt).toBeGreaterThan(49);
+      expect(new Date().getTime() - startedAt).toBeGreaterThan(48);
       expect(value).toBe(1);
       done();
     });
@@ -89,7 +89,7 @@ describe('Open Promise Class', () => {
     const startedAt = new Date().getTime();
 
     op.promise.then(val => {
-      expect(new Date().getTime() - startedAt).toBeGreaterThan(49);
+      expect(new Date().getTime() - startedAt).toBeGreaterThan(48);
       expect(val).toBe(1);
       done();
     });
@@ -106,7 +106,7 @@ describe('Open Promise Class', () => {
         throw new CustomError('bar');
       })
       .catch((err: CustomError) => {
-        expect(new Date().getTime() - startedAt).toBeGreaterThan(49);
+        expect(new Date().getTime() - startedAt).toBeGreaterThan(48);
         expect(err.message).toBe('foo');
         done();
       });
diff --git a/src/promise/static/timeout.spec.ts b/src/promise/static/timeout.spec.ts
index 4f15686..a2ff6b1 100644
--- a/src/promise/static/timeout.spec.ts
+++ b/src/promise/static/timeout.spec.ts
@@ -12,7 +12,7 @@ describe('Promise Timeout Static Function', () => {
 
     Promise.timeout(50)
       .then(() => {
-        expect(new Date().getTime() - startedAt).toBeGreaterThan(49);
+        expect(new Date().getTime() - startedAt).toBeGreaterThan(48);
         done();
       });
   });
@@ -22,7 +22,7 @@ describe('Promise Timeout Static Function', () => {
 
     Promise.timeout(50, 'foo')
       .then(val => {
-        expect(new Date().getTime() - startedAt).toBeGreaterThan(49);
+        expect(new Date().getTime() - startedAt).toBeGreaterThan(48);
         expect(val).toBe('foo');
         done();
       });
diff --git a/src/promise/timeout.spec.ts b/src/promise/timeout.spec.ts
index 6e675c8..1a02067 100644
--- a/src/promise/timeout.spec.ts
+++ b/src/promise/timeout.spec.ts
@@ -12,7 +12,7 @@ describe('Timeout Promise Function', () => {
 
     timeout(50)
       .then(() => {
-        expect(new Date().getTime() - startedAt).toBeGreaterThan(49);
+        expect(new Date().getTime() - startedAt).toBeGreaterThan(48);
         done();
       });
   });
@@ -22,7 +22,7 @@ describe('Timeout Promise Function', () => {
 
     timeout(50, 'foo')
       .then(val => {
-        expect(new Date().getTime() - startedAt).toBeGreaterThan(49);
+        expect(new Date().getTime() - startedAt).toBeGreaterThan(48);
         expect(val).toBe('foo');
         done();
       });