From a9f964dd6a799d4f52134c930c363d9ef87b8bd1 Mon Sep 17 00:00:00 2001
From: taobig <studentht@hotmail.com>
Date: Thu, 28 May 2026 17:23:09 +0800
Subject: [PATCH 1/2] fix: set symbol param only when isIsolated is true

---
 v2/margin_service.go      | 9 ++++++---
 v2/margin_service_test.go | 8 ++++----
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/v2/margin_service.go b/v2/margin_service.go
index 4c67e3e7..4e4f324d 100644
--- a/v2/margin_service.go
+++ b/v2/margin_service.go
@@ -242,9 +242,12 @@ func (s *MarginBorrowRepayService) Do(ctx context.Context, opts ...RequestOption
 	m := params{
 		"asset":      s.asset,
 		"isIsolated": s.isIsolated,
-		"symbol":     s.symbol,
-		"amount":     s.amount,
-		"type":       string(s._type),
+		//"symbol":     s.symbol,
+		"amount": s.amount,
+		"type":   string(s._type),
+	}
+	if s.isIsolated {
+		m["symbol"] = s.symbol // set symbol param only when isIsolated is true
 	}
 	r.setFormParams(m)
 	res = new(TransactionResponse)
diff --git a/v2/margin_service_test.go b/v2/margin_service_test.go
index c1de34ab..a5caaa16 100644
--- a/v2/margin_service_test.go
+++ b/v2/margin_service_test.go
@@ -106,8 +106,8 @@ func (s *marginTestSuite) TestBorrowRepayBorrow() {
 			"asset":      asset,
 			"amount":     amount,
 			"isIsolated": false,
-			"symbol":     "",
-			"type":       string(_type),
+			//"symbol":     "",
+			"type": string(_type),
 		})
 		s.assertRequestEqual(e, r)
 	})
@@ -137,8 +137,8 @@ func (s *marginTestSuite) TestBorrowRepayRepay() {
 			"asset":      asset,
 			"amount":     amount,
 			"isIsolated": false,
-			"symbol":     "",
-			"type":       string(_type),
+			//"symbol":     "",
+			"type": string(_type),
 		})
 		s.assertRequestEqual(e, r)
 	})

From 52e7179ae37626eea4414a6f94fb88002d711834 Mon Sep 17 00:00:00 2001
From: taobig <studentht@hotmail.com>
Date: Sun, 7 Jun 2026 16:50:18 +0800
Subject: [PATCH 2/2] fix: guard against sending empty symbol in isolated
 margin

---
 v2/margin_service.go      | 18 +++++--------
 v2/margin_service_test.go | 56 ++++++++++++++++++++++++++++++++++++---
 2 files changed, 59 insertions(+), 15 deletions(-)

diff --git a/v2/margin_service.go b/v2/margin_service.go
index 4e4f324d..09ef9516 100644
--- a/v2/margin_service.go
+++ b/v2/margin_service.go
@@ -3,6 +3,7 @@ package binance
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"strings"
 )
@@ -242,12 +243,14 @@ func (s *MarginBorrowRepayService) Do(ctx context.Context, opts ...RequestOption
 	m := params{
 		"asset":      s.asset,
 		"isIsolated": s.isIsolated,
-		//"symbol":     s.symbol,
-		"amount": s.amount,
-		"type":   string(s._type),
+		"amount":     s.amount,
+		"type":       string(s._type),
 	}
 	if s.isIsolated {
-		m["symbol"] = s.symbol // set symbol param only when isIsolated is true
+		if s.symbol == "" {
+			return nil, fmt.Errorf("symbol is required for isolated margin borrow/repay")
+		}
+		m["symbol"] = s.symbol // Only set symbol param when isIsolated is true
 	}
 	r.setFormParams(m)
 	res = new(TransactionResponse)
@@ -330,13 +333,6 @@ func (s *ListMarginBorrowRepayService) Do(ctx context.Context, opts ...RequestOp
 		secType:  secTypeSigned,
 	}
 	m := params{
-		//"asset":          s.asset,
-		//"isolatedSymbol": s.isolatedSymbol,
-		//"txId":           s.txId,
-		//"startTime":      s.startTime,
-		//"endTime":        s.endTime,
-		//"current":        s.current,
-		//"size":           s.size,
 		"type": string(s._type),
 	}
 	r.setParams(m)
diff --git a/v2/margin_service_test.go b/v2/margin_service_test.go
index a5caaa16..db133e0e 100644
--- a/v2/margin_service_test.go
+++ b/v2/margin_service_test.go
@@ -106,8 +106,7 @@ func (s *marginTestSuite) TestBorrowRepayBorrow() {
 			"asset":      asset,
 			"amount":     amount,
 			"isIsolated": false,
-			//"symbol":     "",
-			"type": string(_type),
+			"type":       string(_type),
 		})
 		s.assertRequestEqual(e, r)
 	})
@@ -137,8 +136,7 @@ func (s *marginTestSuite) TestBorrowRepayRepay() {
 			"asset":      asset,
 			"amount":     amount,
 			"isIsolated": false,
-			//"symbol":     "",
-			"type": string(_type),
+			"type":       string(_type),
 		})
 		s.assertRequestEqual(e, r)
 	})
@@ -154,6 +152,56 @@ func (s *marginTestSuite) TestBorrowRepayRepay() {
 	s.assertTransactionResponseEqual(e, res)
 }
 
+func (s *marginTestSuite) TestBorrowRepayBorrowIsolated() {
+	data := []byte(`{
+		"tranId": 100000001
+	}`)
+	s.mockDo(data, nil)
+	defer s.assertDo()
+	asset := "BTC"
+	amount := "1.000"
+	symbol := "BTCUSDT"
+	_type := MarginAccountBorrow
+	s.assertReq(func(r *request) {
+		e := newSignedRequest().setFormParams(params{
+			"asset":      asset,
+			"amount":     amount,
+			"isIsolated": true,
+			"symbol":     symbol,
+			"type":       string(_type),
+		})
+		s.assertRequestEqual(e, r)
+	})
+	res, err := s.client.NewMarginBorrowRepayService().
+		Asset(asset).
+		Amount(amount).
+		IsIsolated(true).
+		Symbol(symbol).
+		Type(_type).
+		Do(newContext())
+	s.r().NoError(err)
+	e := &TransactionResponse{
+		TranID: 100000001,
+	}
+	s.assertTransactionResponseEqual(e, res)
+}
+
+func (s *marginTestSuite) TestBorrowRepayBorrowIsolatedWithoutSymbol() {
+	asset := "BTC"
+	amount := "1.000"
+	_type := MarginAccountBorrow
+	res, err := s.client.NewMarginBorrowRepayService().
+		Asset(asset).
+		Amount(amount).
+		IsIsolated(true).
+		Type(_type).
+		Do(newContext())
+	s.r().Error(err)
+	s.r().EqualError(err, "symbol is required for isolated margin borrow/repay")
+	s.r().Nil(res)
+	s.client.AssertNotCalled(s.T(), "do", anyHTTPRequest())
+}
+
 func (s *marginTestSuite) TestListBorrowRepay() {
 	data := []byte(`{
 		  "rows": [