diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128K/ZX128.Port.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128K/ZX128.Port.cs
index ec358785d5..9fe37c4c14 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128K/ZX128.Port.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128K/ZX128.Port.cs
@@ -127,7 +127,11 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
                 */
 
                 // Border - LSB 3 bits hold the border colour
-                ULADevice.BorderColor = value & BORDER_BIT;
+                if (ULADevice.BorderColor != (value & BORDER_BIT))
+                {
+                    ULADevice.RenderScreen((int)CurrentFrameCycle);
+                    ULADevice.BorderColor = value & BORDER_BIT;
+                }
 
                 // Buzzer
                 BuzzerDevice.ProcessPulseValue((value & EAR_BIT) != 0);