diff --git a/src/env.c b/src/env.c
index 7d047def..df8ae2ac 100644
--- a/src/env.c
+++ b/src/env.c
@@ -24,11 +24,9 @@
 #include "env.h"
 #include "lbm_memory.h"
 
-static lbm_value *env_global;
+static lbm_value env_global[GLOBAL_ENV_ROOTS];
 
 int lbm_init_env(void) {
-  env_global = (lbm_value*)lbm_malloc(GLOBAL_ENV_ROOTS * sizeof(lbm_value));
-  if (!env_global) return 0;
   for (int i = 0; i < GLOBAL_ENV_ROOTS; i ++) {
     env_global[i] = ENC_SYM_NIL;
   }
diff --git a/src/heap.c b/src/heap.c
index 9e8e1843..1c5fdd9e 100644
--- a/src/heap.c
+++ b/src/heap.c
@@ -722,18 +722,6 @@ void lbm_gc_mark_phase(lbm_value root) {
     if (t_ptr >= LBM_NON_CONS_POINTER_TYPE_FIRST &&
         t_ptr <= LBM_NON_CONS_POINTER_TYPE_LAST) continue;
 
-    if (cell->car == ENC_SYM_CONT) {
-      lbm_value cont = cell->cdr;
-      lbm_array_header_t *arr = (lbm_array_header_t*)lbm_car(cont);
-      lbm_value *arrdata = (lbm_value *)arr->data;
-      for (lbm_uint i = 0; i < arr->size / 4; i ++) {
-        if (lbm_is_ptr(arrdata[i])){
-          if (!lbm_push (s, arrdata[i])) {
-            lbm_critical_error();
-          }
-        }
-      }
-    }
     if (lbm_is_ptr(cell->cdr)) {
       if (!lbm_push(s, cell->cdr)) {
         lbm_critical_error();
diff --git a/src/print.c b/src/print.c
index 39477151..72c23474 100644
--- a/src/print.c
+++ b/src/print.c
@@ -202,7 +202,7 @@ int print_emit_continuation(lbm_char_channel_t *chan, lbm_value v) {
 int print_emit_custom(lbm_char_channel_t *chan, lbm_value v) {
   lbm_uint *custom = (lbm_uint*)lbm_car(v);
   int r;
-  if (custom[CUSTOM_TYPE_DESCRIPTOR]) {
+  if (custom && custom[CUSTOM_TYPE_DESCRIPTOR]) {
     r = print_emit_string(chan, (char*)custom[CUSTOM_TYPE_DESCRIPTOR]);
   } else {
     r = print_emit_string(chan, "Unspecified_Custom_Type");
diff --git a/tests/test_callcc_6.lisp b/tests/test_callcc_6.lisp
new file mode 100644
index 00000000..f1a44761
--- /dev/null
+++ b/tests/test_callcc_6.lisp
@@ -0,0 +1,9 @@
+
+(let ((r '(1 2 3 4)))
+  (def result (eq r (call-cc (fn (k) (define cc k))))))
+
+(gc)
+
+(cc '(1 2 3 4))
+
+(check result)
diff --git a/tests/test_sort_10.lisp b/tests/test_sort_10.lisp
new file mode 100644
index 00000000..e1707540
--- /dev/null
+++ b/tests/test_sort_10.lisp
@@ -0,0 +1,18 @@
+
+(define r-list '(3 7 12 19 25 8 14 30 5 22 17 11))
+
+(defun cmp (x y)
+  {
+  (gc)
+  (> x y)
+  })
+
+(defun f (x)
+  (if (= x 0)
+      t
+    {
+    (sort cmp r-list)
+    (f (- x 1))
+    }))
+
+(check (f 5))
diff --git a/tests/test_sort_8.lisp b/tests/test_sort_8.lisp
new file mode 100644
index 00000000..5a90bb3d
--- /dev/null
+++ b/tests/test_sort_8.lisp
@@ -0,0 +1,13 @@
+
+(define r-list '(3 7 12 19 25 8 14 30 5 22 17 11))
+
+
+(defun f (x)
+  (if (= x 0)
+      t
+    {
+    (sort > r-list)
+    (f (- x 1))
+    }))
+
+(check (f 10000))
diff --git a/tests/test_sort_9.lisp b/tests/test_sort_9.lisp
new file mode 100644
index 00000000..872627cb
--- /dev/null
+++ b/tests/test_sort_9.lisp
@@ -0,0 +1,14 @@
+
+(define r-list '(3 7 12 19 25 8 14 30 5 22 17 11))
+
+
+(defun f (x)
+  (if (= x 0)
+      t
+    {
+    (sort > r-list)
+    (gc)
+    (f (- x 1))
+    }))
+
+(check (f 100))