diff --git a/harness.c b/harness.c
index 0c9b840..b50f32d 100644
--- a/harness.c
+++ b/harness.c
@@ -14,13 +14,15 @@ typedef unsigned char u_char;
 #include "cmsg_private.h"
 #include "harness.h"
 
+#include <assert.h>
+
 #ifdef __APPLE__
 /* Bollocks. Looks like OS X chokes unless STACK_SIZE is a multiple of 32k. */
 #define STACK_SIZE 32768
 #elif linux
-#define STACK_SIZE 4096
+#define STACK_SIZE 32768
 #else
-#error Define STACK_SIZE for your platform.
+#error Define STACK_SIZE for your platform. It should probably not be less than 32k?
 #endif
 
 Process *current_process = NULL;