diff --git a/src/V3AstNodeExpr.h b/src/V3AstNodeExpr.h
index 7d4a3842d..06cda4604 100644
--- a/src/V3AstNodeExpr.h
+++ b/src/V3AstNodeExpr.h
@@ -5784,6 +5784,7 @@ public:
 };
 class AstOneHot final : public AstNodeUniop {
     // True if only single bit set in vector
+    // @astgen makeDfgVertex
 public:
     AstOneHot(FileLine* fl, AstNodeExpr* lhsp)
         : ASTGEN_SUPER_OneHot(fl, lhsp) {
@@ -5801,6 +5802,7 @@ public:
 };
 class AstOneHot0 final : public AstNodeUniop {
     // True if only single bit, or no bits set in vector
+    // @astgen makeDfgVertex
 public:
     AstOneHot0(FileLine* fl, AstNodeExpr* lhsp)
         : ASTGEN_SUPER_OneHot0(fl, lhsp) {
diff --git a/src/V3Dfg.cpp b/src/V3Dfg.cpp
index df68246aa..d51250bc3 100644
--- a/src/V3Dfg.cpp
+++ b/src/V3Dfg.cpp
@@ -774,7 +774,9 @@ void DfgVertex::typeCheck(const DfgGraph& dfg) const {
     case VDfgType::LogNot:
     case VDfgType::RedAnd:
     case VDfgType::RedOr:
-    case VDfgType::RedXor: {
+    case VDfgType::RedXor:
+    case VDfgType::OneHot:
+    case VDfgType::OneHot0: {
         CHECK(dtype() == DfgDataType::packed(1), "Should be 1-bit");
         CHECK(inputp(0)->isPacked(), "Operand should be Packed type");
         return;
diff --git a/src/V3DfgCse.cpp b/src/V3DfgCse.cpp
index abce554ba..40aa85190 100644
--- a/src/V3DfgCse.cpp
+++ b/src/V3DfgCse.cpp
@@ -110,6 +110,8 @@ class V3DfgCse final {
         case VDfgType::NeqCase:
         case VDfgType::NeqWild:
         case VDfgType::Not:
+        case VDfgType::OneHot:
+        case VDfgType::OneHot0:
         case VDfgType::Or:
         case VDfgType::Pow:
         case VDfgType::PowSS:
@@ -232,6 +234,8 @@ class V3DfgCse final {
         case VDfgType::NeqCase:
         case VDfgType::NeqWild:
         case VDfgType::Not:
+        case VDfgType::OneHot:
+        case VDfgType::OneHot0:
         case VDfgType::Or:
         case VDfgType::Pow:
         case VDfgType::PowSS:
diff --git a/src/V3DfgPeephole.cpp b/src/V3DfgPeephole.cpp
index f8a9a2b46..7c0fc7e25 100644
--- a/src/V3DfgPeephole.cpp
+++ b/src/V3DfgPeephole.cpp
@@ -143,6 +143,8 @@ template <> void foldOp<DfgExtendS>    (V3Number& out, const V3Number& src) { ou
 template <> void foldOp<DfgLogNot>     (V3Number& out, const V3Number& src) { out.opLogNot(src); }
 template <> void foldOp<DfgNegate>     (V3Number& out, const V3Number& src) { out.opNegate(src); }
 template <> void foldOp<DfgNot>        (V3Number& out, const V3Number& src) { out.opNot(src); }
+template <> void foldOp<DfgOneHot>     (V3Number& out, const V3Number& src) { out.opOneHot(src); }
+template <> void foldOp<DfgOneHot0>    (V3Number& out, const V3Number& src) { out.opOneHot0(src); }
 template <> void foldOp<DfgRedAnd>     (V3Number& out, const V3Number& src) { out.opRedAnd(src); }
 template <> void foldOp<DfgRedOr>      (V3Number& out, const V3Number& src) { out.opRedOr(src); }
 template <> void foldOp<DfgRedXor>     (V3Number& out, const V3Number& src) { out.opRedXor(src); }
@@ -1325,6 +1327,14 @@ class V3DfgPeephole final : public DfgVisitor {
         }
     }
 
+    void visit(DfgOneHot* const vtxp) override {
+        if (foldUnary(vtxp)) return;
+    }
+
+    void visit(DfgOneHot0* const vtxp) override {
+        if (foldUnary(vtxp)) return;
+    }
+
     void visit(DfgRedOr* const vtxp) override {
         if (optimizeReduction(vtxp)) return;
     }
diff --git a/test_regress/t/t_dfg_peephole.v b/test_regress/t/t_dfg_peephole.v
index aa15acf60..9e5c64da4 100644
--- a/test_regress/t/t_dfg_peephole.v
+++ b/test_regress/t/t_dfg_peephole.v
@@ -62,6 +62,12 @@ module t (
   //verilator lint_on WIDTH
   `signal(FOLD_UNARY_Extend, tmp_FOLD_UNARY_Extend);
   `signal(FOLD_UNARY_ExtendS, tmp_FOLD_UNARY_ExtendS);
+  `signal(FOLD_UNARY_OneHot,    $onehot(const_a));
+  `signal(FOLD_UNARY_OneHot0,   $onehot0(const_a));
+  `signal(FOLD_UNARY_OneHot_A,  $onehot(const_a[0]));
+  `signal(FOLD_UNARY_OneHot_B,  $onehot(~const_a[0]));
+  `signal(FOLD_UNARY_OneHot0_A, $onehot0(const_a[0]));
+  `signal(FOLD_UNARY_OneHot0_B, $onehot0(~const_a[0]));
 
   `signal(FOLD_BINARY_Add,       const_a + const_b);
   `signal(FOLD_BINARY_And,       const_a & const_b);