diff --git a/src/dev/x86/I8042.py b/src/dev/x86/I8042.py
index 1f6a48410..31192adcd 100644
--- a/src/dev/x86/I8042.py
+++ b/src/dev/x86/I8042.py
@@ -35,6 +35,8 @@ class I8042(BasicPioDevice):
     type = 'I8042'
     cxx_class = 'X86ISA::I8042'
     pio_latency = Param.Latency('1ns', "Programmed IO latency in simticks")
+    # This isn't actually used for anything here.
+    pio_addr = 0x0
     data_port = Param.Addr('Data port address')
     command_port = Param.Addr('Command/status port address')
     mouse_int_pin = Param.X86IntSourcePin(X86IntSourcePin(),
diff --git a/src/dev/x86/I82094AA.py b/src/dev/x86/I82094AA.py
index 5ca58614d..9d57beed1 100644
--- a/src/dev/x86/I82094AA.py
+++ b/src/dev/x86/I82094AA.py
@@ -37,7 +37,7 @@ class I82094AA(BasicPioDevice):
     pio_latency = Param.Latency('1ns', "Programmed IO latency in simticks")
     pio_addr = Param.Addr("Device address")
     int_port = Port("Port for sending and receiving interrupt messages")
-    external_int_pic = Param.I8259("External PIC, if any")
+    external_int_pic = Param.I8259(NULL, "External PIC, if any")
 
     def pin(self, line):
         return X86IntSinkPin(device=self, number=line)
diff --git a/src/dev/x86/I8259.py b/src/dev/x86/I8259.py
index e0128d032..0a516d30a 100644
--- a/src/dev/x86/I8259.py
+++ b/src/dev/x86/I8259.py
@@ -44,7 +44,7 @@ class I8259(BasicPioDevice):
     output = Param.X86IntSourcePin(X86IntSourcePin(),
             'The pin this I8259 drives')
     mode = Param.X86I8259CascadeMode('How this I8259 is cascaded')
-    slave = Param.I8259('Slave I8259, if any')
+    slave = Param.I8259(NULL, 'Slave I8259, if any')
 
     def pin(self, line):
         return X86IntSinkPin(device=self, number=line)