diff --git a/mongoose.c b/mongoose.c
index c4ae5f4e..1154ff99 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -17628,8 +17628,8 @@ struct mg_tcpip_driver mg_tcpip_driver_imxrt = {mg_tcpip_driver_imxrt_init,
 #endif
 
 
-enum {                      // ID1  ID2
-  MG_PHY_KSZ8x = 0x22,      // 0022 1561 - KSZ8081RNB
+enum {                  // ID1  ID2
+  MG_PHY_KSZ8x = 0x22,  // 0022 1561 - KSZ8081RNB
   MG_PHY_DP83x = 0x2000,
   MG_PHY_DP83867 = 0xa231,  // 2000 a231 - TI DP83867I
   MG_PHY_DP83825 = 0xa140,  // 2000 a140 - TI DP83825I
@@ -17658,23 +17658,15 @@ static const char *mg_phy_id_to_str(uint16_t id1, uint16_t id2) {
   switch (id1) {
     case MG_PHY_DP83x:
       switch (id2) {
-        case MG_PHY_DP83867:
-          return "DP83867";
-        case MG_PHY_DP83848:
-          return "DP83848";
-        case MG_PHY_DP83825:
-          return "DP83825";
-        default:
-          return "DP83x";
+        case MG_PHY_DP83867: return "DP83867";
+        case MG_PHY_DP83848: return "DP83848";
+        case MG_PHY_DP83825: return "DP83825";
+        default: return "DP83x";
       }
-    case MG_PHY_KSZ8x:
-      return "KSZ8x";
-    case MG_PHY_LAN87x:
-      return "LAN87x";
-    case MG_PHY_RTL8201:
-      return "RTL8201";
-    default:
-      return "unknown";
+    case MG_PHY_KSZ8x: return "KSZ8x";
+    case MG_PHY_LAN87x: return "LAN87x";
+    case MG_PHY_RTL8201: return "RTL8201";
+    default: return "unknown";
   }
   (void) id2;
 }
@@ -17689,6 +17681,13 @@ void mg_phy_init(struct mg_phy *phy, uint8_t phy_addr, uint8_t config) {
   id2 = phy->read_reg(phy_addr, MG_PHY_REG_ID2);
   MG_INFO(("PHY ID: %#04x %#04x (%s)", id1, id2, mg_phy_id_to_str(id1, id2)));
 
+  if (config & MG_PHY_DISABLE_AUTONEG) {
+    uint16_t val = phy->read_reg(phy_addr, MG_PHY_REG_BCR);
+    phy->write_reg(phy_addr, MG_PHY_REG_BCR, val & (uint16_t) ~MG_BIT(12));
+    val = phy->read_reg(phy_addr, MG_PHY_REG_BCR);
+    phy->write_reg(phy_addr, MG_PHY_REG_BCR, (uint16_t) MG_BIT(9));
+  }
+
   if (id1 == MG_PHY_DP83x && id2 == MG_PHY_DP83867) {
     phy->write_reg(phy_addr, 0x0d, 0x1f);  // write 0x10d to IO_MUX_CFG (0x0170)
     phy->write_reg(phy_addr, 0x0e, 0x170);
diff --git a/mongoose.h b/mongoose.h
index 1dd4ffaa..5a9d974c 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -2928,13 +2928,10 @@ struct mg_phy {
   void (*write_reg)(uint8_t addr, uint8_t reg, uint16_t value);
 };
 
-// PHY configuration settings, bitmask
-enum {
-  // Set if PHY LEDs are connected to ground
-  MG_PHY_LEDS_ACTIVE_HIGH = (1 << 0),
-  // Set when PHY clocks MAC. Otherwise, MAC clocks PHY
-  MG_PHY_CLOCKS_MAC = (1 << 1),
-};
+// MG_TCPIP_PHY_CONF configuration settings, bitmask of the following:
+#define MG_PHY_LEDS_ACTIVE_HIGH 1  // PHY LEDs are connected to ground
+#define MG_PHY_CLOCKS_MAC 2        // PHY clocks MAC. Otherwise, MAC clocks PHY
+#define MG_PHY_DISABLE_AUTONEG 4   // Disable autonegotiation
 
 enum { MG_PHY_SPEED_10M, MG_PHY_SPEED_100M, MG_PHY_SPEED_1000M };
 
diff --git a/src/drivers/phy.c b/src/drivers/phy.c
index 2af18ed1..5f924f86 100644
--- a/src/drivers/phy.c
+++ b/src/drivers/phy.c
@@ -1,7 +1,7 @@
 #include "phy.h"
 
-enum {                      // ID1  ID2
-  MG_PHY_KSZ8x = 0x22,      // 0022 1561 - KSZ8081RNB
+enum {                  // ID1  ID2
+  MG_PHY_KSZ8x = 0x22,  // 0022 1561 - KSZ8081RNB
   MG_PHY_DP83x = 0x2000,
   MG_PHY_DP83867 = 0xa231,  // 2000 a231 - TI DP83867I
   MG_PHY_DP83825 = 0xa140,  // 2000 a140 - TI DP83825I
@@ -30,23 +30,15 @@ static const char *mg_phy_id_to_str(uint16_t id1, uint16_t id2) {
   switch (id1) {
     case MG_PHY_DP83x:
       switch (id2) {
-        case MG_PHY_DP83867:
-          return "DP83867";
-        case MG_PHY_DP83848:
-          return "DP83848";
-        case MG_PHY_DP83825:
-          return "DP83825";
-        default:
-          return "DP83x";
+        case MG_PHY_DP83867: return "DP83867";
+        case MG_PHY_DP83848: return "DP83848";
+        case MG_PHY_DP83825: return "DP83825";
+        default: return "DP83x";
       }
-    case MG_PHY_KSZ8x:
-      return "KSZ8x";
-    case MG_PHY_LAN87x:
-      return "LAN87x";
-    case MG_PHY_RTL8201:
-      return "RTL8201";
-    default:
-      return "unknown";
+    case MG_PHY_KSZ8x: return "KSZ8x";
+    case MG_PHY_LAN87x: return "LAN87x";
+    case MG_PHY_RTL8201: return "RTL8201";
+    default: return "unknown";
   }
   (void) id2;
 }
@@ -61,6 +53,13 @@ void mg_phy_init(struct mg_phy *phy, uint8_t phy_addr, uint8_t config) {
   id2 = phy->read_reg(phy_addr, MG_PHY_REG_ID2);
   MG_INFO(("PHY ID: %#04x %#04x (%s)", id1, id2, mg_phy_id_to_str(id1, id2)));
 
+  if (config & MG_PHY_DISABLE_AUTONEG) {
+    uint16_t val = phy->read_reg(phy_addr, MG_PHY_REG_BCR);
+    phy->write_reg(phy_addr, MG_PHY_REG_BCR, val & (uint16_t) ~MG_BIT(12));
+    val = phy->read_reg(phy_addr, MG_PHY_REG_BCR);
+    phy->write_reg(phy_addr, MG_PHY_REG_BCR, (uint16_t) MG_BIT(9));
+  }
+
   if (id1 == MG_PHY_DP83x && id2 == MG_PHY_DP83867) {
     phy->write_reg(phy_addr, 0x0d, 0x1f);  // write 0x10d to IO_MUX_CFG (0x0170)
     phy->write_reg(phy_addr, 0x0e, 0x170);
diff --git a/src/drivers/phy.h b/src/drivers/phy.h
index 30ae6ba3..dd5402f6 100644
--- a/src/drivers/phy.h
+++ b/src/drivers/phy.h
@@ -7,13 +7,10 @@ struct mg_phy {
   void (*write_reg)(uint8_t addr, uint8_t reg, uint16_t value);
 };
 
-// PHY configuration settings, bitmask
-enum {
-  // Set if PHY LEDs are connected to ground
-  MG_PHY_LEDS_ACTIVE_HIGH = (1 << 0),
-  // Set when PHY clocks MAC. Otherwise, MAC clocks PHY
-  MG_PHY_CLOCKS_MAC = (1 << 1),
-};
+// MG_TCPIP_PHY_CONF configuration settings, bitmask of the following:
+#define MG_PHY_LEDS_ACTIVE_HIGH 1  // PHY LEDs are connected to ground
+#define MG_PHY_CLOCKS_MAC 2        // PHY clocks MAC. Otherwise, MAC clocks PHY
+#define MG_PHY_DISABLE_AUTONEG 4   // Disable autonegotiation
 
 enum { MG_PHY_SPEED_10M, MG_PHY_SPEED_100M, MG_PHY_SPEED_1000M };