diff --git a/CMakeLists.txt b/CMakeLists.txt
index c6036c51..8ccd0188 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -444,6 +444,7 @@ if (ISLE_BUILD_CONFIG)
     LEGO1/mxdirectx/mxdirect3d.cpp
     CONFIG/config.cpp
     CONFIG/ConfigCommandLineInfo.cpp
+    CONFIG/common.cpp
     CONFIG/AboutDlg.cpp
     CONFIG/MainDlg.cpp
     CONFIG/detectdx5.cpp
diff --git a/CONFIG/AboutDlg.cpp b/CONFIG/AboutDlg.cpp
index 055cb5c4..b14704f1 100644
--- a/CONFIG/AboutDlg.cpp
+++ b/CONFIG/AboutDlg.cpp
@@ -6,25 +6,14 @@ DECOMP_SIZE_ASSERT(CDialog, 0x60)
 DECOMP_SIZE_ASSERT(CAboutDialog, 0x60)
 
 // FUNCTION: CONFIG 0x00403c20
-CAboutDialog::CAboutDialog() : CDialog(IDD)
+CAboutDialog::CAboutDialog() : CCommonDialog(IDD)
 {
 }
 
-// FUNCTION: CONFIG 0x00403c90
-void CAboutDialog::BeginModalState()
-{
-	::EnableWindow(m_hWnd, FALSE);
-}
-
-// FUNCTION: CONFIG 0x00403ca0
-void CAboutDialog::EndModalState()
-{
-	::EnableWindow(m_hWnd, TRUE);
-}
-
 // FUNCTION: CONFIG 0x00403d20
 void CAboutDialog::DoDataExchange(CDataExchange* pDX)
 {
 }
+
 BEGIN_MESSAGE_MAP(CAboutDialog, CDialog)
 END_MESSAGE_MAP()
diff --git a/CONFIG/AboutDlg.h b/CONFIG/AboutDlg.h
index 4c5c9e59..19c25dda 100644
--- a/CONFIG/AboutDlg.h
+++ b/CONFIG/AboutDlg.h
@@ -1,13 +1,15 @@
 #if !defined(AFX_ABOUTDLG_H)
 #define AFX_ABOUTDLG_H
 
+#include "common.h"
+
 #include "afxwin.h"
 #include "compat.h"
 #include "res/resource.h"
 
 // VTABLE: CONFIG 0x00406308
 // SIZE 0x60
-class CAboutDialog : public CDialog {
+class CAboutDialog : public CCommonDialog {
 public:
 	CAboutDialog();
 	// Dialog Data
@@ -22,8 +24,6 @@ class CAboutDialog : public CDialog {
 
 protected:
 	void DoDataExchange(CDataExchange* pDX) override;
-	void BeginModalState() override;
-	void EndModalState() override;
 	//}}AFX_VIRTUAL
 	//    void UpdateInterface();
 	//    void SwitchToAdvanced(BOOL p_advanced);
diff --git a/CONFIG/MainDlg.cpp b/CONFIG/MainDlg.cpp
index e2f52209..52f55e58 100644
--- a/CONFIG/MainDlg.cpp
+++ b/CONFIG/MainDlg.cpp
@@ -10,7 +10,7 @@ DECOMP_SIZE_ASSERT(CDialog, 0x60)
 DECOMP_SIZE_ASSERT(CMainDialog, 0x70)
 
 // FUNCTION: CONFIG 0x00403d50
-CMainDialog::CMainDialog(CWnd* pParent) : CDialog(IDD, pParent)
+CMainDialog::CMainDialog(CWnd* pParent) : CCommonDialog(IDD, pParent)
 {
 	afxCurrentWinApp;
 	m_icon = LoadIconA(AfxFindResourceHandle(MAKEINTRESOURCE(IDI_CONFIG), RT_GROUP_ICON), MAKEINTRESOURCE(IDI_CONFIG));
diff --git a/CONFIG/MainDlg.h b/CONFIG/MainDlg.h
index 5abfaf5a..10564a9e 100644
--- a/CONFIG/MainDlg.h
+++ b/CONFIG/MainDlg.h
@@ -1,6 +1,8 @@
 #if !defined(AFX_MAINDLG_H)
 #define AFX_MAINDLG_H
 
+#include "common.h"
+
 #include "afxwin.h"
 #include "compat.h"
 #include "decomp.h"
@@ -8,7 +10,7 @@
 
 // VTABLE: CONFIG 0x004063e0
 // SIZE 0x70
-class CMainDialog : public CDialog {
+class CMainDialog : public CCommonDialog {
 public:
 	CMainDialog(CWnd* pParent);
 	// Dialog Data
@@ -23,8 +25,6 @@ class CMainDialog : public CDialog {
 
 protected:
 	void DoDataExchange(CDataExchange* pDX) override;
-	void BeginModalState() override {}
-	void EndModalState() override {}
 	//}}AFX_VIRTUAL
 	void UpdateInterface();
 	void SwitchToAdvanced(BOOL p_advanced);
diff --git a/CONFIG/common.cpp b/CONFIG/common.cpp
new file mode 100644
index 00000000..173f0bd1
--- /dev/null
+++ b/CONFIG/common.cpp
@@ -0,0 +1,26 @@
+#include "common.h"
+
+
+// FUNCTION: CONFIG 0x00402ca0
+void CSerializer::Serialize(CArchive& ar) {
+}
+
+// FUNCTION: CONFIG 0x00402cb0
+void CSerializer::AssertValid() const {
+}
+
+// FUNCTION: CONFIG 0x00402cc0
+void CSerializer::Dump(CDumpContext& dc) const {
+}
+
+// FUNCTION: CONFIG 0x00403c90
+void CCommonDialog::BeginModalState()
+{
+    ::EnableWindow(m_hWnd, FALSE);
+}
+
+// FUNCTION: CONFIG 0x00403ca0
+void CCommonDialog::EndModalState()
+{
+    ::EnableWindow(m_hWnd, TRUE);
+}
diff --git a/CONFIG/common.h b/CONFIG/common.h
new file mode 100644
index 00000000..7dee96c2
--- /dev/null
+++ b/CONFIG/common.h
@@ -0,0 +1,23 @@
+#ifndef AFX_COMMON_H
+#define AFX_COMMON_H
+
+#include <afxwin.h>
+
+#include "compat.h"
+
+class CSerializer {
+public:
+    void Serialize(CArchive& ar);
+    void AssertValid() const;
+    void Dump(CDumpContext& dc) const;
+};
+
+class CCommonDialog : public CDialog {
+public:
+    CCommonDialog(UINT nIDTemplate, CWnd* pParentWnd = NULL) : CDialog(nIDTemplate, pParentWnd) { }
+
+    void BeginModalState() override;
+    void EndModalState() override;
+};
+
+#endif