diff --git a/src/mzscheme/gc2/newgc.c b/src/mzscheme/gc2/newgc.c
index 7a2c50c94c..66b0f84a41 100644
--- a/src/mzscheme/gc2/newgc.c
+++ b/src/mzscheme/gc2/newgc.c
@@ -367,8 +367,6 @@ static size_t round_to_apage_size(size_t sizeb)
 static unsigned long custodian_single_time_limit(int set);
 inline static int thread_get_owner(void *p);
 
-static int atomic_counter = 0;
-
 /* the core allocation functions */
 static void *allocate_big(size_t sizeb, int type)
 {
diff --git a/src/mzscheme/gc2/rlimit_heapsize.c b/src/mzscheme/gc2/rlimit_heapsize.c
index c172966e87..36e9b96767 100644
--- a/src/mzscheme/gc2/rlimit_heapsize.c
+++ b/src/mzscheme/gc2/rlimit_heapsize.c
@@ -16,7 +16,7 @@ static size_type determine_max_heap_size(void)
   getrlimit(RLIMIT_DATA, &rlim);
 # endif
 
-  return (rlim.rlim_cur == RLIM_INFINITY) ? (1024 * 1024 * 1024) : rlim.rlim_cur;
+  return (rlim.rlim_cur == RLIM_INFINITY) ? (unsigned long)-1 : rlim.rlim_cur;
 }
 
 #endif
diff --git a/src/mzscheme/gc2/vm_osx.c b/src/mzscheme/gc2/vm_osx.c
index 2a4a05890a..85f91a306e 100644
--- a/src/mzscheme/gc2/vm_osx.c
+++ b/src/mzscheme/gc2/vm_osx.c
@@ -207,7 +207,7 @@ static unsigned long determine_max_heap_size()
 
   getrlimit(RLIMIT_RSS, rlim);
   retval = rlim->rlim_cur; free(rlim);
-  return (retval == RLIM_INFINITY) ? (1024 * 1024 * 1024) : retval;
+  return (retval == RLIM_INFINITY) ? (unsigned long)-1 : retval;
 }
 #endif