diff --git a/src/V3Dfg.cpp b/src/V3Dfg.cpp
index 76676790e..3f7e60ee3 100644
--- a/src/V3Dfg.cpp
+++ b/src/V3Dfg.cpp
@@ -692,7 +692,10 @@ void DfgVertex::typeCheck(const DfgGraph& dfg) const {
     }
 
     case VDfgType::SAnd:
-    case VDfgType::SOr: UASSERT_OBJ(false, this, "SAnd/SOr should be removed before DFG"); return;
+    case VDfgType::SOr:
+    case VDfgType::SThroughout:
+        UASSERT_OBJ(false, this, "SAnd/SOr/SThroughout should be removed before DFG");
+        return;
 
     case VDfgType::LogAnd:
     case VDfgType::LogEq:
diff --git a/src/V3DfgCse.cpp b/src/V3DfgCse.cpp
index 0257c4117..b6149d9f1 100644
--- a/src/V3DfgCse.cpp
+++ b/src/V3DfgCse.cpp
@@ -126,6 +126,7 @@ class V3DfgCse final {
         case VDfgType::StreamR:
         case VDfgType::SAnd:
         case VDfgType::SOr:
+        case VDfgType::SThroughout:
         case VDfgType::Sub:
         case VDfgType::Xor: return V3Hash{};
         }
@@ -246,6 +247,7 @@ class V3DfgCse final {
         case VDfgType::StreamL:
         case VDfgType::SAnd:
         case VDfgType::SOr:
+        case VDfgType::SThroughout:
         case VDfgType::StreamR:
         case VDfgType::Sub:
         case VDfgType::Xor: return true;