diff --git a/spinn_machine/version/version_48_chips.py b/spinn_machine/version/version_48_chips.py
index 2ce94bc9..5c7a5d29 100644
--- a/spinn_machine/version/version_48_chips.py
+++ b/spinn_machine/version/version_48_chips.py
@@ -48,14 +48,21 @@ def get_potential_ethernet_chips(
 
     @overrides(AbstractVersion._verify_size)
     def _verify_size(self, width: int, height: int):
-        if width == height == 8:
-            # 1 board
-            return
-        if width % 12 not in [0, 4]:
+        if width == 8:
+            if height == 8:
+                # 1 board
+                return
+            else:
+                raise SpinnMachineException(
+                    f"{width=} and {height=} not supported")
+        elif height == 8:
+            raise SpinnMachineException(
+                f"{width=} and {height=} not supported")
+        if width % 4 != 0:
             raise SpinnMachineException(
                 f"{width=} must be a multiple of 12 "
                 f"or a multiple of 12 plus 4")
-        if height % 12 not in [0, 4]:
+        if height % 4 != 0:
             raise SpinnMachineException(
                 f"{height=} must be a multiple of 12 "
                 f"or a multiple of 12 plus 4")
diff --git a/unittests/test_virtual_machine5.py b/unittests/test_virtual_machine5.py
index 9dad23c1..5536f96b 100644
--- a/unittests/test_virtual_machine5.py
+++ b/unittests/test_virtual_machine5.py
@@ -286,6 +286,10 @@ def test_fpga_links_3_board(self):
         for ip, fpga, fpga_link, x, y, link in fpga_links:
             self._assert_fpga_link(machine, fpga, fpga_link, x, y, link, ip)
 
+    def test_none_triad(self):
+        set_config("Machine", "version", FIVE)
+        virtual_machine(width=20, height=16)
+        virtual_machine(width=12, height=16)
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/unittests/version/test_version248.py b/unittests/version/test_version248.py
index dc6031ae..9b0ddd99 100644
--- a/unittests/version/test_version248.py
+++ b/unittests/version/test_version248.py
@@ -124,6 +124,8 @@ def test_verify_size(self):
         version.verify_size(12, 16)
         version.verify_size(16, 12)
         version.verify_size(16, 16)
+        version.verify_size(16, 20)
+        version.verify_size(20, 16)
 
     def test_create_machine(self):
         version = Version248()