diff --git a/src/V3Ast.cpp b/src/V3Ast.cpp
index 377f8b8c7..7b77b1073 100644
--- a/src/V3Ast.cpp
+++ b/src/V3Ast.cpp
@@ -23,10 +23,6 @@
 #include <memory>
 #include <sstream>
 
-#ifdef VL_ALLOC_RANDOM_CHECKS
-#include "V3Ast__gen_sizeof.h"
-#endif
-
 VL_DEFINE_DEBUG_FUNCTIONS;
 
 //======================================================================
@@ -998,6 +994,15 @@ void AstNode::operator delete(void* objp, size_t size) {
 
 #ifdef VL_ALLOC_RANDOM_CHECKS
 void* AstNode::operator new(size_t size) {  // VL_MT_SAFE
+    // Compute the maximum node size once and cache it
+    static const size_t ASTGEN_MAX_NODE_SIZE = []() {
+        size_t maxSize = 0;
+        for (size_t t = 0; t < VNType::NUM_TYPES(); ++t) {
+            maxSize = std::max(maxSize, VNType::typeInfo(static_cast<VNType::en>(t)).m_sizeof);
+        }
+        return maxSize;
+    }();
+
     // Make the following small to debug this routine, larger for performance and better random
     constexpr size_t POOL_SIZE = 65536;  // Ideally large enough to fit all nodes used in tests
     // Randomly select from a large pool (POOL_SIZE) of max-node sized (MAX_NODE_SIZE) pointers
diff --git a/src/astgen b/src/astgen
index 1865f51f6..3d26c0474 100755
--- a/src/astgen
+++ b/src/astgen
@@ -935,16 +935,6 @@ def write_ast_type_info(filename):
                 ))
 
 
-def write_ast_sizeof(filename):
-    with open_file(filename) as fh:
-        fh.write("static constexpr size_t ASTGEN_MAX_NODE_SIZE =\n")
-        paren = ""
-        for node in AstNodeList:
-            fh.write("    std::max(sizeof(Ast{n}),\n".format(n=node.name))
-            paren += ")"
-        fh.write("    static_cast<size_t>(0)" + paren + ";\n")
-
-
 def write_ast_impl(filename):
     with open_file(filename) as fh:
 
@@ -1594,7 +1584,6 @@ if Args.classes:
     write_ast_impl("V3Ast__gen_impl.h")
     write_ast_macros("V3Ast__gen_macros.h")
     write_ast_yystype("V3Ast__gen_yystype.h")
-    write_ast_sizeof("V3Ast__gen_sizeof.h")
     # Write Dfg code
     write_forward_class_decls("Dfg", DfgVertexList)
     write_visitor_decls("Dfg", DfgVertexList)