diff --git a/src/c/stacks.d b/src/c/stacks.d
index f2e730bb2..45636d946 100644
--- a/src/c/stacks.d
+++ b/src/c/stacks.d
@@ -873,6 +873,43 @@ ecl_stack_push(cl_object self, cl_object elt)
   return self;
 }
 
+cl_object
+ecl_stack_pop(cl_object self)
+{
+  cl_index fillp = self->vector.fillp;
+  cl_object elt = ECL_NIL;
+  if (ecl_unlikely(fillp == 0)) {
+    ecl_internal_error("ecl_stack_pop: stack underflow");
+  }
+  elt = self->vector.self.t[fillp-1];
+  self->vector.self.t[fillp-1] = ECL_NIL;
+  self->vector.fillp--;
+  return elt;
+}
+
+cl_object
+ecl_stack_psh(cl_object self, cl_object elt)
+{
+  cl_index fillp = self->vector.fillp;
+  cl_index dim = self->vector.dim;
+  if (ecl_unlikely(fillp == dim)) {
+    ecl_internal_error("ecl_stack_psh: stack overflow");
+  }
+  self->vector.self.t[self->vector.fillp++] = elt;
+  return self;
+}
+
+cl_object
+ecl_stack_dup(cl_object self)
+{
+  cl_index fillp = self->vector.fillp;
+  if (ecl_unlikely(fillp == 0)) {
+    ecl_internal_error("ecl_stack_dup: empty stack");
+  }
+  ecl_stack_push(self, self->vector.self.t[fillp-1]);
+  return self;
+}
+
 cl_object
 ecl_stack_del(cl_object self, cl_object elt)
 {
@@ -898,3 +935,22 @@ ecl_stack_popu(cl_object self)
   self->vector.self.t[self->vector.fillp] = ECL_NIL;
   return result;
 }
+
+cl_object
+ecl_stack_pshu(cl_object self, cl_object elt)
+{
+  self->vector.self.t[self->vector.fillp++] = elt;
+  return elt;
+}
+
+void
+ecl_stack_grow(cl_object self, cl_index n)
+{
+  self->vector.fillp += n;
+}
+
+void
+ecl_stack_drop(cl_object self, cl_index n)
+{
+  self->vector.fillp -= n;
+}
diff --git a/src/h/external.h b/src/h/external.h
index 80857562b..65735d8d5 100755
--- a/src/h/external.h
+++ b/src/h/external.h
@@ -311,7 +311,10 @@ extern ECL_API void ecl_free_stack(cl_object o);
 extern ECL_API void ecl_wipe_stack(cl_object o);
 extern ECL_API cl_object ecl_stack_push(cl_object stack, cl_object elt);
 extern ECL_API cl_object ecl_stack_del(cl_object stack, cl_object elt);
+extern ECL_API cl_object ecl_stack_pop(cl_object stack);
+extern ECL_API cl_object ecl_stack_psh(cl_object stack, cl_object elt);
 extern ECL_API cl_object ecl_stack_popu(cl_object stack);
+extern ECL_API cl_object ecl_stack_pshu(cl_object stack, cl_object elt);
 
 /* array.c */