diff --git a/Sources/Classes/Headers/Public/RSClient.h b/Sources/Classes/Headers/Public/RSClient.h
index 78d83535..a8ba8e5c 100644
--- a/Sources/Classes/Headers/Public/RSClient.h
+++ b/Sources/Classes/Headers/Public/RSClient.h
@@ -51,6 +51,7 @@ typedef void (^Callback)(NSObject *_Nullable);
 - (void) group:(NSString *)groupId traits:(NSDictionary<NSString*, id>*)traits;
 - (void) group:(NSString *)groupId;
 
+- (void) alias:(NSString *)newId previousId:(NSString * _Nullable)previousId options:(RSOption * _Nullable) options;
 - (void) alias:(NSString *)newId options:(RSOption * _Nullable) options;
 - (void) alias:(NSString *)newId;
 
diff --git a/Sources/Classes/RSClient.m b/Sources/Classes/RSClient.m
index 3cc6a058..66831379 100644
--- a/Sources/Classes/RSClient.m
+++ b/Sources/Classes/RSClient.m
@@ -225,10 +225,14 @@ - (void)alias:(NSString *)newId {
         [self reportDiscardedEvent];
         return;
     }
-    [self alias:newId options:nil];
+    [self alias:newId previousId:nil options:nil];
 }
 
 - (void) alias:(NSString *)newId options:(RSOption *) options {
+    [self alias:newId previousId:nil options:options];
+}
+
+- (void) alias:(NSString *)newId previousId:(NSString *)previousId options:(RSOption *) options {
     if ([RSClient getOptStatus]) {
         [self reportDiscardedEvent];
         return;
@@ -236,7 +240,7 @@ - (void) alias:(NSString *)newId options:(RSOption *) options {
     RSContext *rc = [RSElementCache getContext];
     NSMutableDictionary<NSString*,NSObject*>* traits = [rc.traits mutableCopy];
     
-    NSObject *prevId = [traits objectForKey:@"userId"] ?: [traits objectForKey:@"id"] ?: self.anonymousId;
+    NSObject *prevId = previousId ?: [traits objectForKey:@"userId"] ?: [traits objectForKey:@"id"] ?: self.anonymousId;
     
     traits[@"id"] = newId;
     traits[@"userId"] = newId;