diff --git a/BasiliskII/src/ether.cpp b/BasiliskII/src/ether.cpp
index b4924250..756680b9 100644
--- a/BasiliskII/src/ether.cpp
+++ b/BasiliskII/src/ether.cpp
@@ -453,7 +453,7 @@ void ether_udp_read(uint32 packet, int length, struct sockaddr_in *from)
  *  Ethernet packet allocator
  */
 
-#if SIZEOF_VOID_P == 4 || REAL_ADDRESSING == 0
+#if SIZEOF_VOID_P != 4 || REAL_ADDRESSING == 0
 static uint32 ether_packet = 0;			// Ethernet packet (cached allocation)
 static uint32 n_ether_packets = 0;		// Number of ethernet packets allocated so far (should be at most 1)