diff --git a/Changes b/Changes
index 016f91f50..acac7dee0 100644
--- a/Changes
+++ b/Changes
@@ -15,6 +15,7 @@ Verilator 4.221 devel
 
 * Split --prof-threads into --prof-exec and --prof-pgo (#3365). [Geza Lore, Shunyao CAD]
 * Deprecate 'vluint64_t' and similar types (#3255).
+* Raise error on assignment to const in initial blocks. [Geza Lore, Shunyao CAD]
 * Fix MSVC localtime_s (#3124).
 * Fix Bison 3.8.2 error (#3366). [elike-ypq]
 * Fix rare bug in -Oz (V3Localize) (#3286). [Geza Lore, Shunyao CAD]
diff --git a/src/V3Active.cpp b/src/V3Active.cpp
index 043f05233..a0ed963ef 100644
--- a/src/V3Active.cpp
+++ b/src/V3Active.cpp
@@ -422,6 +422,14 @@ private:
     virtual void visit(AstActive* nodep) override {
         // Actives are being formed, so we can ignore any already made
     }
+    virtual void visit(AstInitialStatic* nodep) override {
+        // Relink to IACTIVE, unless already under it
+        UINFO(4, "    INITIAL " << nodep << endl);
+        const ActiveDlyVisitor dlyvisitor{nodep, ActiveDlyVisitor::CT_INITIAL};
+        AstActive* const wantactivep = m_namer.getIActive(nodep->fileline());
+        nodep->unlinkFrBack();
+        wantactivep->addStmtsp(nodep);
+    }
     virtual void visit(AstInitial* nodep) override {
         // Relink to IACTIVE, unless already under it
         UINFO(4, "    INITIAL " << nodep << endl);
diff --git a/src/V3AstNodes.h b/src/V3AstNodes.h
index 1c86aad29..5082ae08d 100644
--- a/src/V3AstNodes.h
+++ b/src/V3AstNodes.h
@@ -3407,7 +3407,7 @@ public:
 };
 
 class AstInitialAutomatic final : public AstNodeProcedure {
-    // initial for automatic variables
+    // Automatic variable initialization
     // That is, it runs every function start, or class construction
 public:
     AstInitialAutomatic(FileLine* fl, AstNode* bodysp)
@@ -3415,6 +3415,15 @@ public:
     ASTNODE_NODE_FUNCS(InitialAutomatic)
 };
 
+class AstInitialStatic final : public AstNodeProcedure {
+    // Static variable initialization
+    // That is, it runs at the beginning of simulation, before 'initial' blocks
+public:
+    AstInitialStatic(FileLine* fl, AstNode* bodysp)
+        : ASTGEN_SUPER_InitialStatic(fl, bodysp) {}
+    ASTNODE_NODE_FUNCS(InitialStatic)
+};
+
 class AstAlways final : public AstNodeProcedure {
     const VAlwaysKwd m_keyword;
 
diff --git a/src/V3Cdc.cpp b/src/V3Cdc.cpp
index 871a5fd8c..acb305ab0 100644
--- a/src/V3Cdc.cpp
+++ b/src/V3Cdc.cpp
@@ -716,6 +716,7 @@ private:
     // Ignores
     virtual void visit(AstInitial*) override {}
     virtual void visit(AstInitialAutomatic*) override {}
+    virtual void visit(AstInitialStatic*) override {}
     virtual void visit(AstTraceDecl*) override {}
     virtual void visit(AstCoverToggle*) override {}
     virtual void visit(AstNodeDType*) override {}
diff --git a/src/V3Class.cpp b/src/V3Class.cpp
index c7bbc91c3..6a7a3ce4f 100644
--- a/src/V3Class.cpp
+++ b/src/V3Class.cpp
@@ -153,6 +153,11 @@ private:
         iterateChildren(nodep);
         if (m_packageScopep) { m_toScopeMoves.push_back(std::make_pair(nodep, m_packageScopep)); }
     }
+    virtual void visit(AstInitialStatic* nodep) override {
+        // But not AstInitialAutomatic, which remains under the class
+        iterateChildren(nodep);
+        if (m_packageScopep) { m_toScopeMoves.push_back(std::make_pair(nodep, m_packageScopep)); }
+    }
 
     virtual void visit(AstNodeMath* nodep) override {}  // Short circuit
     virtual void visit(AstNodeStmt* nodep) override {}  // Short circuit
@@ -173,7 +178,7 @@ public:
                 vscp->scopep(scopep);
                 vscp->unlinkFrBack();
                 scopep->addVarp(vscp);
-            } else if (VN_IS(nodep, Initial)) {
+            } else if (VN_IS(nodep, Initial) || VN_IS(nodep, InitialStatic)) {
                 nodep->unlinkFrBack();
                 scopep->addActivep(nodep);
             } else {
diff --git a/src/V3EmitV.cpp b/src/V3EmitV.cpp
index e04c15e4d..594795fa5 100644
--- a/src/V3EmitV.cpp
+++ b/src/V3EmitV.cpp
@@ -99,6 +99,7 @@ class EmitVBaseVisitor VL_NOT_FINAL : public EmitCBaseVisitor {
         putqs(nodep, "end\n");
     }
     virtual void visit(AstInitialAutomatic* nodep) override { iterateChildrenConst(nodep); }
+    virtual void visit(AstInitialStatic* nodep) override { iterateChildrenConst(nodep); }
     virtual void visit(AstAlways* nodep) override {
         putfs(nodep, "always ");
         if (m_sensesp) {
diff --git a/src/V3LinkParse.cpp b/src/V3LinkParse.cpp
index b99b8e3a9..df1e36436 100644
--- a/src/V3LinkParse.cpp
+++ b/src/V3LinkParse.cpp
@@ -275,7 +275,7 @@ private:
                 if (nodep->lifetime().isAutomatic()) {
                     nodep->addNextHere(new AstInitialAutomatic{newfl, assp});
                 } else {
-                    nodep->addNextHere(new AstInitial{newfl, assp});
+                    nodep->addNextHere(new AstInitialStatic{newfl, assp});
                 }
             }  // 4. Under blocks, it's an initial value to be under an assign
             else {
diff --git a/src/V3Order.cpp b/src/V3Order.cpp
index 090e81b7d..9007ce8f2 100644
--- a/src/V3Order.cpp
+++ b/src/V3Order.cpp
@@ -662,6 +662,9 @@ class OrderBuildVisitor final : public VNVisitor {
     virtual void visit(AstInitialAutomatic* nodep) override {  //
         iterateLogic(nodep);
     }
+    virtual void visit(AstInitialStatic* nodep) override {  //
+        iterateLogic(nodep);
+    }
     virtual void visit(AstAlways* nodep) override {  //
         iterateLogic(nodep);
     }
diff --git a/src/V3Width.cpp b/src/V3Width.cpp
index f4c350d6e..45a78ac8c 100644
--- a/src/V3Width.cpp
+++ b/src/V3Width.cpp
@@ -2041,7 +2041,8 @@ private:
         if (nodep->access().isWriteOrRW() && nodep->varp()->direction() == VDirection::CONSTREF) {
             nodep->v3error("Assigning to const ref variable: " << nodep->prettyNameQ());
         } else if (nodep->access().isWriteOrRW() && nodep->varp()->isConst() && !m_paramsOnly
-                   && (!m_ftaskp || !m_ftaskp->isConstructor()) && !VN_IS(m_procedurep, Initial)) {
+                   && (!m_ftaskp || !m_ftaskp->isConstructor())
+                   && !VN_IS(m_procedurep, InitialStatic)) {
             // Too loose, but need to allow our generated first assignment
             // Move this to a property of the AstInitial block
             nodep->v3error("Assigning to const variable: " << nodep->prettyNameQ());