diff --git a/gc.c b/gc.c
index a51b19ed..07024c7b 100644
--- a/gc.c
+++ b/gc.c
@@ -1357,28 +1357,28 @@ void *gc_alloc(gc_heap_root * hrt, size_t size, char *obj, gc_thread_data * thd,
   size = gc_heap_align(size);
   if (size <= 32) {
     heap_type = HEAP_SM;
-    try_alloc = &gc_try_alloc;
-    try_alloc_slow = &gc_try_alloc_slow;
+    //try_alloc = &gc_try_alloc;
+    //try_alloc_slow = &gc_try_alloc_slow;
     // TODO:
-    //try_alloc = &gc_try_alloc_fixed_size;
-    //try_alloc_slow = &gc_try_alloc_slow_fixed_size;
+    try_alloc = &gc_try_alloc_fixed_size;
+    try_alloc_slow = &gc_try_alloc_slow_fixed_size;
   } else if (size <= 64) {
     heap_type = HEAP_64;
-    try_alloc = &gc_try_alloc;
-    try_alloc_slow = &gc_try_alloc_slow;
+    //try_alloc = &gc_try_alloc;
+    //try_alloc_slow = &gc_try_alloc_slow;
     // TODO:
-    //try_alloc = &gc_try_alloc_fixed_size;
-    //try_alloc_slow = &gc_try_alloc_slow_fixed_size;
+    try_alloc = &gc_try_alloc_fixed_size;
+    try_alloc_slow = &gc_try_alloc_slow_fixed_size;
 // Only use this heap on 64-bit platforms, where larger objs are used more often
 // Code from http://stackoverflow.com/a/32717129/101258
 #if INTPTR_MAX == INT64_MAX
   } else if (size <= 96) {
     heap_type = HEAP_96;
-    try_alloc = &gc_try_alloc;
-    try_alloc_slow = &gc_try_alloc_slow;
+    //try_alloc = &gc_try_alloc;
+    //try_alloc_slow = &gc_try_alloc_slow;
     // TODO:
-    //try_alloc = &gc_try_alloc_fixed_size;
-    //try_alloc_slow = &gc_try_alloc_slow_fixed_size;
+    try_alloc = &gc_try_alloc_fixed_size;
+    try_alloc_slow = &gc_try_alloc_slow_fixed_size;
 #endif
   } else if (size >= MAX_STACK_OBJ) {
     heap_type = HEAP_HUGE;
diff --git a/include/cyclone/types.h b/include/cyclone/types.h
index 85d3609e..903620b1 100644
--- a/include/cyclone/types.h
+++ b/include/cyclone/types.h
@@ -172,12 +172,12 @@ typedef enum {
 
 /** The first heap type that is not fixed-size */
 // TODO: disable this for now
-#define LAST_FIXED_SIZE_HEAP_TYPE -1
-//#if INTPTR_MAX == INT64_MAX
-//#define LAST_FIXED_SIZE_HEAP_TYPE HEAP_96
-//#else
-//#define LAST_FIXED_SIZE_HEAP_TYPE HEAP_64
-//#endif
+//#define LAST_FIXED_SIZE_HEAP_TYPE -1
+#if INTPTR_MAX == INT64_MAX
+#define LAST_FIXED_SIZE_HEAP_TYPE HEAP_96
+#else
+#define LAST_FIXED_SIZE_HEAP_TYPE HEAP_64
+#endif
 
 /** The number of `gc_heap_type`'s */
 #define NUM_HEAP_TYPES (HEAP_HUGE + 1)