diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus2a/ZX128Plus2a.Port.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus2a/ZX128Plus2a.Port.cs
index 6809731766..9e97b56867 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus2a/ZX128Plus2a.Port.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus2a/ZX128Plus2a.Port.cs
@@ -75,7 +75,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             AYDevice.WritePort(port, value);
 
             // port 0x7ffd - hardware should only respond when bits 1 & 15 are reset and bit 14 is set
-            if (port == 0x7ffd)
+            if (!portBits[1] && !portBits[15] && portBits[14])
             {
                 if (!PagingDisabled)
                 {
@@ -95,7 +95,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
                 }
             }
             // port 0x1ffd - hardware should only respond when bits 1, 13, 14 & 15 are reset and bit 12 is set
-            if (port == 0x1ffd)
+            if (!portBits[1] && portBits[12] && !portBits[13] && !portBits[14] && !portBits[15])
             {
                 if (!PagingDisabled)
                 {
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus3/ZX128Plus3.Port.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus3/ZX128Plus3.Port.cs
index 5e13f828ca..e9c8494fff 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus3/ZX128Plus3.Port.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/ZXSpectrum128KPlus3/ZX128Plus3.Port.cs
@@ -81,7 +81,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             UPDDiskDevice.WritePort(port, value);
 
             // port 0x7ffd - hardware should only respond when bits 1 & 15 are reset and bit 14 is set
-            if (port == 0x7ffd)
+            if (!portBits[1] && !portBits[15] && portBits[14])
             {
                 if (!PagingDisabled)
                 {
@@ -101,7 +101,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
                 }                         
             }
             // port 0x1ffd - hardware should only respond when bits 1, 13, 14 & 15 are reset and bit 12 is set
-            if (port == 0x1ffd)
+            if (!portBits[1] && portBits[12] && !portBits[13] && !portBits[14] && !portBits[15])
             {
                 if (!PagingDisabled)
                 {