diff --git a/src/mzscheme/gc2/alloc_cache.c b/src/mzscheme/gc2/alloc_cache.c
index 695da4330e..d23df78654 100644
--- a/src/mzscheme/gc2/alloc_cache.c
+++ b/src/mzscheme/gc2/alloc_cache.c
@@ -42,16 +42,7 @@ static void *malloc_dirty_pages(size_t len, size_t alignment)
   return do_malloc_pages(len, alignment, 1);
 }
 
-typedef struct {
-  void *start;
-  long len;
-  short age;
-  short zeroed;
-} Free_Block;
-
 #define BLOCKFREE_UNMAP_AGE 1
-#define BLOCKFREE_CACHE_SIZE 96
-static Free_Block blockfree[BLOCKFREE_CACHE_SIZE];
 
 static int compare_free_block(const void *a, const void *b)
 {
@@ -64,6 +55,7 @@ static int compare_free_block(const void *a, const void *b)
 static void collapse_adjacent_pages(void)
 {
   int i, j;
+  Free_Block *blockfree = GC->blockfree;
 
   /* collapse adjacent: */
   my_qsort(blockfree, BLOCKFREE_CACHE_SIZE, sizeof(Free_Block), compare_free_block);
@@ -84,6 +76,7 @@ inline static void *find_cached_pages(size_t len, size_t alignment, int dirty_ok
 {
   int i;
   void *r;
+  Free_Block *blockfree = GC->blockfree;
 
   /* Try an exact fit: */
   for (i = 0; i < BLOCKFREE_CACHE_SIZE; i++) {
@@ -136,6 +129,7 @@ inline static void *find_cached_pages(size_t len, size_t alignment, int dirty_ok
 static void return_mem_to_cache(void *p, size_t len, int zeroed)
 {
   int i;
+  Free_Block *blockfree = GC->blockfree;
 
   /* Round up to nearest page: */
   if (len & (page_size - 1))
@@ -187,6 +181,7 @@ static void free_pages(void *p, size_t len)
 static void flush_freed_pages(void)
 {
   int i;
+  Free_Block *blockfree = GC->blockfree;
 
   collapse_adjacent_pages();
 
diff --git a/src/mzscheme/gc2/commongc_internal.h b/src/mzscheme/gc2/commongc_internal.h
index 46b9fcaa92..68c8c342cf 100644
--- a/src/mzscheme/gc2/commongc_internal.h
+++ b/src/mzscheme/gc2/commongc_internal.h
@@ -67,3 +67,12 @@ typedef struct finalizer {
   struct finalizer *right;
 } Fnl;
 
+typedef struct {
+  void *start;
+  long len;
+  short age;
+  short zeroed;
+} Free_Block;
+
+
+#define BLOCKFREE_CACHE_SIZE 96
diff --git a/src/mzscheme/gc2/compactgc_internal.h b/src/mzscheme/gc2/compactgc_internal.h
index e112989442..0aa038e099 100644
--- a/src/mzscheme/gc2/compactgc_internal.h
+++ b/src/mzscheme/gc2/compactgc_internal.h
@@ -19,8 +19,10 @@ typedef struct CompactGC {
   GC_Weak_Box   *weak_boxes;
   GC_Ephemeron  *ephemerons;
   int num_last_seen_ephemerons;
+  Free_Block    *blockfree;
 } CompactGC;
 
-void CompactGC_initialize(CompactGC *newgc) {
-  memset(newgc, 0, sizeof(CompactGC));
+void CompactGC_initialize(CompactGC *gc) {
+  memset(gc, 0, sizeof(CompactGC));
+  gc->blockfree = malloc(sizeof(Free_Block) *BLOCKFREE_CACHE_SIZE);
 }
diff --git a/src/mzscheme/gc2/newgc.h b/src/mzscheme/gc2/newgc.h
index 0386496fe6..c62d705ef0 100644
--- a/src/mzscheme/gc2/newgc.h
+++ b/src/mzscheme/gc2/newgc.h
@@ -158,6 +158,7 @@ typedef struct NewGC {
   GC_Weak_Box   *weak_boxes;
   GC_Ephemeron  *ephemerons;
   int num_last_seen_ephemerons;
+  Free_Block    *blockfree;
 } NewGC;
 
 void NewGC_initialize(NewGC *newgc) {
@@ -169,6 +170,7 @@ void NewGC_initialize(NewGC *newgc) {
 #else
   newgc->page_maps = malloc(PAGEMAP32_SIZE * sizeof (mpage*)); 
 #endif
+  newgc->blockfree = malloc(sizeof(Free_Block) * BLOCKFREE_CACHE_SIZE);
   
   newgc->generations_available = 1;
   newgc->last_full_mem_use = (20 * 1024 * 1024);