diff --git a/merge.go b/merge.go
index c6a8225..552681a 100644
--- a/merge.go
+++ b/merge.go
@@ -197,40 +197,3 @@ func keyExists(k string, m map[string]interface{}) string {
 	}
 	return ""
 }
-
-func isNil(value interface{}, traceSource ...bool) bool {
-	if value == nil {
-		return true
-	}
-	var rv reflect.Value
-	if v, ok := value.(reflect.Value); ok {
-		rv = v
-	} else {
-		rv = reflect.ValueOf(value)
-	}
-	switch rv.Kind() {
-	case reflect.Chan,
-		reflect.Map,
-		reflect.Slice,
-		reflect.Func,
-		reflect.Interface,
-		reflect.UnsafePointer:
-		return !rv.IsValid() || rv.IsNil()
-
-	case reflect.Ptr:
-		if len(traceSource) > 0 && traceSource[0] {
-			for rv.Kind() == reflect.Ptr {
-				rv = rv.Elem()
-			}
-			if !rv.IsValid() {
-				return true
-			}
-			if rv.Kind() == reflect.Ptr {
-				return rv.IsNil()
-			}
-		} else {
-			return !rv.IsValid() || rv.IsNil()
-		}
-	}
-	return false
-}