diff --git a/Source/CMakeLists.txt b/Source/CMakeLists.txt
index 0316532123..8117916832 100644
--- a/Source/CMakeLists.txt
+++ b/Source/CMakeLists.txt
@@ -662,8 +662,6 @@ set(SRCS
   cmTryCompileCommand.h
   cmTryRunCommand.cxx
   cmTryRunCommand.h
-  cmUnexpectedCommand.cxx
-  cmUnexpectedCommand.h
   cmUnsetCommand.cxx
   cmUnsetCommand.h
   cmUseMangledMesaCommand.cxx
diff --git a/Source/cmState.cxx b/Source/cmState.cxx
index 57ae324cf4..82b0a52cf1 100644
--- a/Source/cmState.cxx
+++ b/Source/cmState.cxx
@@ -5,6 +5,7 @@
 #include "cmsys/RegularExpression.hxx"
 #include <algorithm>
 #include <assert.h>
+#include <stdlib.h>
 #include <string.h>
 #include <utility>
 
@@ -15,12 +16,13 @@
 #include "cmCommand.h"
 #include "cmDefinitions.h"
 #include "cmDisallowedCommand.h"
+#include "cmExecutionStatus.h"
 #include "cmGlobVerificationManager.h"
 #include "cmListFileCache.h"
+#include "cmMakefile.h"
 #include "cmStatePrivate.h"
 #include "cmStateSnapshot.h"
 #include "cmSystemTools.h"
-#include "cmUnexpectedCommand.h"
 #include "cmake.h"
 
 cmState::cmState()
@@ -419,11 +421,15 @@ void cmState::SetIsGeneratorMultiConfig(bool b)
 
 void cmState::AddBuiltinCommand(std::string const& name,
                                 std::unique_ptr<cmCommand> command)
+{
+  this->AddBuiltinCommand(name, cmLegacyCommandWrapper(std::move(command)));
+}
+
+void cmState::AddBuiltinCommand(std::string const& name, Command command)
 {
   assert(name == cmSystemTools::LowerCase(name));
   assert(this->BuiltinCommands.find(name) == this->BuiltinCommands.end());
-  this->BuiltinCommands.emplace(name,
-                                cmLegacyCommandWrapper(std::move(command)));
+  this->BuiltinCommands.emplace(name, std::move(command));
 }
 
 void cmState::AddDisallowedCommand(std::string const& name,
@@ -438,8 +444,18 @@ void cmState::AddDisallowedCommand(std::string const& name,
 
 void cmState::AddUnexpectedCommand(std::string const& name, const char* error)
 {
-  this->AddBuiltinCommand(name,
-                          cm::make_unique<cmUnexpectedCommand>(name, error));
+  this->AddBuiltinCommand(
+    name,
+    [name, error](std::vector<cmListFileArgument> const&,
+                  cmExecutionStatus& status) -> bool {
+      const char* versionValue =
+        status.GetMakefile().GetDefinition("CMAKE_MINIMUM_REQUIRED_VERSION");
+      if (name == "endif" && (!versionValue || atof(versionValue) <= 1.4)) {
+        return true;
+      }
+      status.SetError(error);
+      return false;
+    });
 }
 
 void cmState::AddScriptedCommand(std::string const& name,
diff --git a/Source/cmState.h b/Source/cmState.h
index ed70bd6f94..a6e9386d8e 100644
--- a/Source/cmState.h
+++ b/Source/cmState.h
@@ -153,6 +153,7 @@ public:
 
   void AddBuiltinCommand(std::string const& name,
                          std::unique_ptr<cmCommand> command);
+  void AddBuiltinCommand(std::string const& name, Command command);
   void AddDisallowedCommand(std::string const& name,
                             std::unique_ptr<cmCommand> command,
                             cmPolicies::PolicyID policy, const char* message);
diff --git a/Source/cmUnexpectedCommand.cxx b/Source/cmUnexpectedCommand.cxx
deleted file mode 100644
index a8de9e689a..0000000000
--- a/Source/cmUnexpectedCommand.cxx
+++ /dev/null
@@ -1,22 +0,0 @@
-/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
-   file Copyright.txt or https://cmake.org/licensing for details.  */
-#include "cmUnexpectedCommand.h"
-
-#include <stdlib.h>
-
-#include "cmMakefile.h"
-
-class cmExecutionStatus;
-
-bool cmUnexpectedCommand::InitialPass(std::vector<std::string> const&,
-                                      cmExecutionStatus&)
-{
-  const char* versionValue =
-    this->Makefile->GetDefinition("CMAKE_MINIMUM_REQUIRED_VERSION");
-  if (this->Name == "endif" && (!versionValue || atof(versionValue) <= 1.4)) {
-    return true;
-  }
-
-  this->SetError(this->Error);
-  return false;
-}
diff --git a/Source/cmUnexpectedCommand.h b/Source/cmUnexpectedCommand.h
deleted file mode 100644
index 6e4cee507b..0000000000
--- a/Source/cmUnexpectedCommand.h
+++ /dev/null
@@ -1,40 +0,0 @@
-/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
-   file Copyright.txt or https://cmake.org/licensing for details.  */
-#ifndef cmUnexpectedCommand_h
-#define cmUnexpectedCommand_h
-
-#include "cmConfigure.h" // IWYU pragma: keep
-
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "cm_memory.hxx"
-
-#include "cmCommand.h"
-
-class cmExecutionStatus;
-
-class cmUnexpectedCommand : public cmCommand
-{
-public:
-  cmUnexpectedCommand(std::string name, const char* error)
-    : Name(std::move(name))
-    , Error(error)
-  {
-  }
-
-  std::unique_ptr<cmCommand> Clone() override
-  {
-    return cm::make_unique<cmUnexpectedCommand>(this->Name, this->Error);
-  }
-
-  bool InitialPass(std::vector<std::string> const& args,
-                   cmExecutionStatus& status) override;
-
-private:
-  std::string Name;
-  const char* Error;
-};
-
-#endif
diff --git a/bootstrap b/bootstrap
index c2194febf2..bb5229b5f4 100755
--- a/bootstrap
+++ b/bootstrap
@@ -440,7 +440,6 @@ CMAKE_CXX_SOURCES="\
   cmTimestamp \
   cmTryCompileCommand \
   cmTryRunCommand \
-  cmUnexpectedCommand \
   cmUnsetCommand \
   cmUVHandlePtr \
   cmUVProcessChain \