From f0f240209f745dbe84572aa9bd9aee0b3ab34702 Mon Sep 17 00:00:00 2001
From: Edmund Lam <elam@hudson-trading.com>
Date: Mon, 6 Jul 2026 10:41:35 -0400
Subject: [PATCH] UASSERT_OBJ

---
 src/V3Param.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/V3Param.cpp b/src/V3Param.cpp
index 19afee32d..1383ef665 100644
--- a/src/V3Param.cpp
+++ b/src/V3Param.cpp
@@ -2266,8 +2266,9 @@ public:
                     }
                 } else if (const AstVarRef* const refp = VN_CAST(np, VarRef)) {
                     AstVar* const varp = refp->varp();
-                    if (varp->varType() == VVarType::LPARAM && deferredVarps.count(varp)
-                        && reachedDeferred.insert(varp).second && varp->valuep()) {
+                    if (varp && varp->varType() == VVarType::LPARAM && deferredVarps.count(varp)
+                        && reachedDeferred.insert(varp).second) {
+                        UASSERT_OBJ(varp->valuep(), varp, "VarRef should have non-null valuep");
                         worklist.push_back(varp->valuep());
                     }
                 }