diff --git a/src/optimization/GVN.cpp b/src/optimization/GVN.cpp
index 1accee1c77bbfb1986a1d79a6364594cc44c5a40..e97b75ba1db19637e1ea60d520dd84fddeda0f55 100644
--- a/src/optimization/GVN.cpp
+++ b/src/optimization/GVN.cpp
@@ -275,9 +275,15 @@ GVN::intersect(shared_ptr<CongruenceClass> ci, shared_ptr<CongruenceClass> cj) {
             c->index_ = exact_idx;
             c->value_expr_ = c->value_phi_ =
                 PhiExpression::create(ci->value_expr_, cj->value_expr_);
-        } else if (ci->value_expr_->get_expr_type() == Expression::e_call) {
+        } else {
+            if (c->value_expr_ == nullptr) {
+                c->value_expr_ =
+                    PhiExpression::create(ci->value_expr_, cj->value_expr_);
+            }
+            if (c->value_phi_ == nullptr)
+                c->value_phi_ =
+                    PhiExpression::create(ci->value_expr_, cj->value_expr_);
         }
-
         // ??
         c->leader_ = *c->members_.begin();
     }