diff --git a/reactos/base/applications/charmap/precomp.h b/reactos/base/applications/charmap/precomp.h
index a87f118d866..4e0324c3de5 100644
--- a/reactos/base/applications/charmap/precomp.h
+++ b/reactos/base/applications/charmap/precomp.h
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef __CHARMAP_PRECOMP_H
+#define __CHARMAP_PRECOMP_H
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -52,3 +53,5 @@ VOID ShowAboutDlg(HWND hWndParent);
 
 BOOL RegisterMapClasses(HINSTANCE hInstance);
 VOID UnregisterMapClasses(HINSTANCE hInstance);
+
+#endif /* __CHARMAP_PRECOMP_H */
diff --git a/reactos/base/applications/mscutils/devmgmt/precomp.h b/reactos/base/applications/mscutils/devmgmt/precomp.h
index 8723d8d1d55..d9bdd425f85 100644
--- a/reactos/base/applications/mscutils/devmgmt/precomp.h
+++ b/reactos/base/applications/mscutils/devmgmt/precomp.h
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef __DEVMGMT_PRECOMP_H
+#define __DEVMGMT_PRECOMP_H
 
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
@@ -92,3 +93,5 @@ HIMAGELIST InitImageList(UINT NumButtons,
 
 VOID GetError(VOID);
 VOID DisplayString(LPTSTR);
+
+#endif /* __DEVMGMT_PRECOMP_H */
diff --git a/reactos/base/applications/mscutils/servman/precomp.h b/reactos/base/applications/mscutils/servman/precomp.h
index a81b984c7d3..9b829ad78df 100644
--- a/reactos/base/applications/mscutils/servman/precomp.h
+++ b/reactos/base/applications/mscutils/servman/precomp.h
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef __SERVMAN_PRECOMP_H
+#define __SERVMAN_PRECOMP_H
 
 //#define WIN32_LEAN_AND_MEAN
 #include <windows.h>
@@ -184,3 +185,5 @@ HIMAGELIST InitImageList(UINT StartResource,
                          UINT Width,
                          UINT Height,
                          ULONG type);
+
+#endif /* __SERVMAN_PRECOMP_H */
diff --git a/reactos/base/applications/taskmgr/precomp.h b/reactos/base/applications/taskmgr/precomp.h
index 67272472a48..c30856b3065 100644
--- a/reactos/base/applications/taskmgr/precomp.h
+++ b/reactos/base/applications/taskmgr/precomp.h
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef __PRECOMP_H
+#define __PRECOMP_H
 
 #ifndef UNICODE
 #error Task-Manager uses NDK functions, so it can only be compiled with Unicode support enabled!
@@ -35,3 +36,5 @@
 #include "priority.h"
 #include "run.h"
 #include "trayicon.h"
+
+#endif /* __PRECOMP_H */
diff --git a/reactos/base/shell/cmd/precomp.h b/reactos/base/shell/cmd/precomp.h
index f36368e1d59..915246cceb8 100644
--- a/reactos/base/shell/cmd/precomp.h
+++ b/reactos/base/shell/cmd/precomp.h
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef __CMD_PRECOMP_H
+#define __CMD_PRECOMP_H
 
 #ifdef _MSC_VER
 #pragma warning ( disable : 4103 ) /* use #pragma pack to change alignment */
@@ -42,3 +43,5 @@ WINE_DEFAULT_DEBUG_CHANNEL(cmd);
 #else
 #define debugstr_aw debugstr_a
 #endif
+
+#endif /* __CMD_PRECOMP_H */
diff --git a/reactos/base/system/smss/smss.h b/reactos/base/system/smss/smss.h
index 8c467e566dc..61f3b4bead4 100644
--- a/reactos/base/system/smss/smss.h
+++ b/reactos/base/system/smss/smss.h
@@ -1,4 +1,5 @@
-#pragma once
+#ifndef _SMSS_H_INCLUDED_
+#define _SMSS_H_INCLUDED_
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -112,4 +113,7 @@ NTSTATUS SmInitializeDbgSs(VOID);
 VOID NTAPI DisplayString(LPCWSTR lpwString);
 VOID NTAPI PrintString (char* fmt, ...);
 
+#endif /* _SMSS_H_INCLUDED_ */
+
 /* EOF */
+