--- a/src/mame/drivers/cmi.cpp
+++ b/src/mame/drivers/cmi.cpp
@@ -128,7 +128,10 @@
 
 #define NUM_Q256_CARDS          1   // Max of 2
 #define NUM_CHANNEL_CARDS       8
-
+// Page size is defined in limits.h
+#ifdef PAGE_SIZE
+#undef PAGE_SIZE
+#endif
 #define PAGE_SIZE               2048
 #define PAGE_COUNT              (65536 / PAGE_SIZE)
 #define PAGE_MASK               (PAGE_SIZE - 1)
--- a/src/mame/drivers/sun4.cpp
+++ b/src/mame/drivers/sun4.cpp
@@ -456,6 +456,9 @@
 #define PM_ACCESSED     (0x02000000)    // accessed flag
 #define PM_MODIFIED     (0x01000000)    // modified flag
 
+#ifdef PAGE_SIZE
+#undef PAGE_SIZE
+#endif
 #define PAGE_SIZE       (0x00000400)
 
 // DMA controller constants