diff --git a/strutil/string.go b/strutil/string.go
index 02a2b2c..b8785fa 100644
--- a/strutil/string.go
+++ b/strutil/string.go
@@ -121,40 +121,48 @@ func UpperSnakeCase(s string) string {
 // Before returns the substring of the source string up to the first occurrence of the specified string.
 // Play: https://go.dev/play/p/JAWTZDS4F5w
 func Before(s, char string) string {
-	if s == "" || char == "" {
+	i := strings.Index(s, char)
+
+	if s == "" || char == "" || i == -1 {
 		return s
 	}
-	i := strings.Index(s, char)
+
 	return s[0:i]
 }
 
 // BeforeLast returns the substring of the source string up to the last occurrence of the specified string.
 // Play: https://go.dev/play/p/pJfXXAoG_Te
 func BeforeLast(s, char string) string {
-	if s == "" || char == "" {
+	i := strings.LastIndex(s, char)
+
+	if s == "" || char == "" || i == -1 {
 		return s
 	}
-	i := strings.LastIndex(s, char)
+
 	return s[0:i]
 }
 
 // After returns the substring after the first occurrence of a specified string in the source string.
 // Play: https://go.dev/play/p/RbCOQqCDA7m
 func After(s, char string) string {
-	if s == "" || char == "" {
+	i := strings.Index(s, char)
+
+	if s == "" || char == "" || i == -1 {
 		return s
 	}
-	i := strings.Index(s, char)
+
 	return s[i+len(char):]
 }
 
 // AfterLast returns the substring after the last occurrence of a specified string in the source string.
 // Play: https://go.dev/play/p/1TegARrb8Yn
 func AfterLast(s, char string) string {
-	if s == "" || char == "" {
+	i := strings.LastIndex(s, char)
+
+	if s == "" || char == "" || i == -1 {
 		return s
 	}
-	i := strings.LastIndex(s, char)
+
 	return s[i+len(char):]
 }
 
diff --git a/strutil/string_test.go b/strutil/string_test.go
index ce39059..10c6135 100644
--- a/strutil/string_test.go
+++ b/strutil/string_test.go
@@ -230,6 +230,8 @@ func TestBefore(t *testing.T) {
 
 	assert.Equal("lancet", Before("lancet", ""))
 	assert.Equal("", Before("lancet", "lancet"))
+	assert.Equal("lancet", Before("lancet", "abcdef"))
+
 	assert.Equal("github.com", Before("github.com/test/lancet", "/"))
 	assert.Equal("github.com/", Before("github.com/test/lancet", "test"))
 }
@@ -240,10 +242,10 @@ func TestBeforeLast(t *testing.T) {
 	assert := internal.NewAssert(t, "TestBeforeLast")
 
 	assert.Equal("lancet", BeforeLast("lancet", ""))
+	assert.Equal("lancet", BeforeLast("lancet", "abcdef"))
+
 	assert.Equal("github.com/test", BeforeLast("github.com/test/lancet", "/"))
 	assert.Equal("github.com/test/", BeforeLast("github.com/test/test/lancet", "test"))
-
-	assert.NotEqual("github.com/", BeforeLast("github.com/test/test/lancet", "test"))
 }
 
 func TestAfter(t *testing.T) {
@@ -255,6 +257,8 @@ func TestAfter(t *testing.T) {
 	assert.Equal("", After("lancet", "lancet"))
 	assert.Equal("test/lancet", After("github.com/test/lancet", "/"))
 	assert.Equal("/lancet", After("github.com/test/lancet", "test"))
+
+	assert.Equal("lancet", After("lancet", "abcdef"))
 }
 
 func TestAfterLast(t *testing.T) {
@@ -266,8 +270,7 @@ func TestAfterLast(t *testing.T) {
 	assert.Equal("lancet", AfterLast("github.com/test/lancet", "/"))
 	assert.Equal("/lancet", AfterLast("github.com/test/lancet", "test"))
 	assert.Equal("/lancet", AfterLast("github.com/test/test/lancet", "test"))
-
-	assert.NotEqual("/test/lancet", AfterLast("github.com/test/test/lancet", "test"))
+	assert.Equal("lancet", AfterLast("lancet", "abcdef"))
 }
 
 func TestIsString(t *testing.T) {