diff --git a/dlls/msi/action.h b/dlls/msi/action.h
index 24ad5ce5255..be7d031c37b 100644
--- a/dlls/msi/action.h
+++ b/dlls/msi/action.h
@@ -18,6 +18,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#ifndef __MSI_ACTION_H__
+#define __MSI_ACTION_H__
+
 #include "wine/list.h"
 
 #define IDENTIFIER_SIZE 96
@@ -214,64 +217,64 @@ typedef struct tagMSISCRIPT
     UINT    InWhatSequence;
     LPWSTR  *UniqueActions;
     UINT    UniqueActionsCount;
-}MSISCRIPT;
+} MSISCRIPT;
 
 
-UINT ACTION_PerformAction(MSIPACKAGE *package, const WCHAR *action, BOOL force);
-UINT ACTION_PerformUIAction(MSIPACKAGE *package, const WCHAR *action);
-void ACTION_FinishCustomActions( MSIPACKAGE* package);
-UINT ACTION_CustomAction(MSIPACKAGE *package,const WCHAR *action, BOOL execute);
+extern UINT ACTION_PerformAction(MSIPACKAGE *package, const WCHAR *action, BOOL force);
+extern UINT ACTION_PerformUIAction(MSIPACKAGE *package, const WCHAR *action);
+extern void ACTION_FinishCustomActions( MSIPACKAGE* package);
+extern UINT ACTION_CustomAction(MSIPACKAGE *package,const WCHAR *action, BOOL execute);
 
 /* actions in other modules */
-UINT ACTION_AppSearch(MSIPACKAGE *package);
-UINT ACTION_FindRelatedProducts(MSIPACKAGE *package);
-UINT ACTION_InstallFiles(MSIPACKAGE *package);
-UINT ACTION_DuplicateFiles(MSIPACKAGE *package);
-UINT ACTION_RegisterClassInfo(MSIPACKAGE *package);
-UINT ACTION_RegisterProgIdInfo(MSIPACKAGE *package);
-UINT ACTION_RegisterExtensionInfo(MSIPACKAGE *package);
-UINT ACTION_RegisterMIMEInfo(MSIPACKAGE *package);
+extern UINT ACTION_AppSearch(MSIPACKAGE *package);
+extern UINT ACTION_FindRelatedProducts(MSIPACKAGE *package);
+extern UINT ACTION_InstallFiles(MSIPACKAGE *package);
+extern UINT ACTION_DuplicateFiles(MSIPACKAGE *package);
+extern UINT ACTION_RegisterClassInfo(MSIPACKAGE *package);
+extern UINT ACTION_RegisterProgIdInfo(MSIPACKAGE *package);
+extern UINT ACTION_RegisterExtensionInfo(MSIPACKAGE *package);
+extern UINT ACTION_RegisterMIMEInfo(MSIPACKAGE *package);
 
 
 /* Helpers */
-DWORD deformat_string(MSIPACKAGE *package, LPCWSTR ptr, WCHAR** data );
-WCHAR *load_dynamic_stringW(MSIRECORD *row, INT index);
-LPWSTR load_dynamic_property(MSIPACKAGE *package, LPCWSTR prop, UINT* rc);
-LPWSTR resolve_folder(MSIPACKAGE *package, LPCWSTR name, BOOL source, 
+extern DWORD deformat_string(MSIPACKAGE *package, LPCWSTR ptr, WCHAR** data );
+extern WCHAR *load_dynamic_stringW(MSIRECORD *row, INT index);
+extern LPWSTR load_dynamic_property(MSIPACKAGE *package, LPCWSTR prop, UINT* rc);
+extern LPWSTR resolve_folder(MSIPACKAGE *package, LPCWSTR name, BOOL source, 
                       BOOL set_prop, MSIFOLDER **folder);
-MSICOMPONENT *get_loaded_component( MSIPACKAGE* package, LPCWSTR Component );
-MSIFEATURE *get_loaded_feature( MSIPACKAGE* package, LPCWSTR Feature );
-MSIFILE *get_loaded_file( MSIPACKAGE* package, LPCWSTR file );
-MSIFOLDER *get_loaded_folder( MSIPACKAGE *package, LPCWSTR dir );
-int track_tempfile(MSIPACKAGE *package, LPCWSTR name, LPCWSTR path);
-UINT schedule_action(MSIPACKAGE *package, UINT script, LPCWSTR action);
-UINT build_icon_path(MSIPACKAGE *, LPCWSTR, LPWSTR *);
-DWORD build_version_dword(LPCWSTR);
-LPWSTR build_directory_name(DWORD , ...);
-BOOL create_full_pathW(const WCHAR *path);
-BOOL ACTION_VerifyComponentForAction(MSIPACKAGE*, MSICOMPONENT*, INSTALLSTATE);
-BOOL ACTION_VerifyFeatureForAction(MSIFEATURE*, INSTALLSTATE);
-void reduce_to_longfilename(WCHAR*);
-void reduce_to_shortfilename(WCHAR*);
-LPWSTR create_component_advertise_string(MSIPACKAGE*, MSICOMPONENT*, LPCWSTR);
-void ACTION_UpdateComponentStates(MSIPACKAGE *package, LPCWSTR szFeature);
-UINT register_unique_action(MSIPACKAGE *, LPCWSTR);
-BOOL check_unique_action(MSIPACKAGE *, LPCWSTR);
-WCHAR* generate_error_string(MSIPACKAGE *, UINT, DWORD, ... );
+extern MSICOMPONENT *get_loaded_component( MSIPACKAGE* package, LPCWSTR Component );
+extern MSIFEATURE *get_loaded_feature( MSIPACKAGE* package, LPCWSTR Feature );
+extern MSIFILE *get_loaded_file( MSIPACKAGE* package, LPCWSTR file );
+extern MSIFOLDER *get_loaded_folder( MSIPACKAGE *package, LPCWSTR dir );
+extern int track_tempfile(MSIPACKAGE *package, LPCWSTR name, LPCWSTR path);
+extern UINT schedule_action(MSIPACKAGE *package, UINT script, LPCWSTR action);
+extern UINT build_icon_path(MSIPACKAGE *, LPCWSTR, LPWSTR *);
+extern DWORD build_version_dword(LPCWSTR);
+extern LPWSTR build_directory_name(DWORD , ...);
+extern BOOL create_full_pathW(const WCHAR *path);
+extern BOOL ACTION_VerifyComponentForAction(MSIPACKAGE*, MSICOMPONENT*, INSTALLSTATE);
+extern BOOL ACTION_VerifyFeatureForAction(MSIFEATURE*, INSTALLSTATE);
+extern void reduce_to_longfilename(WCHAR*);
+extern void reduce_to_shortfilename(WCHAR*);
+extern LPWSTR create_component_advertise_string(MSIPACKAGE*, MSICOMPONENT*, LPCWSTR);
+extern void ACTION_UpdateComponentStates(MSIPACKAGE *package, LPCWSTR szFeature);
+extern UINT register_unique_action(MSIPACKAGE *, LPCWSTR);
+extern BOOL check_unique_action(MSIPACKAGE *, LPCWSTR);
+extern WCHAR* generate_error_string(MSIPACKAGE *, UINT, DWORD, ... );
 
 
 /* control event stuff */
-VOID ControlEvent_FireSubscribedEvent(MSIPACKAGE *package, LPCWSTR event,
+extern VOID ControlEvent_FireSubscribedEvent(MSIPACKAGE *package, LPCWSTR event,
                                       MSIRECORD *data);
-VOID ControlEvent_CleanupSubscriptions(MSIPACKAGE *package);
-VOID ControlEvent_SubscribeToEvent(MSIPACKAGE *package, LPCWSTR event,
+extern VOID ControlEvent_CleanupSubscriptions(MSIPACKAGE *package);
+extern VOID ControlEvent_SubscribeToEvent(MSIPACKAGE *package, LPCWSTR event,
                                    LPCWSTR control, LPCWSTR attribute);
-VOID ControlEvent_UnSubscribeToEvent( MSIPACKAGE *package, LPCWSTR event,
+extern VOID ControlEvent_UnSubscribeToEvent( MSIPACKAGE *package, LPCWSTR event,
                                       LPCWSTR control, LPCWSTR attribute );
 
 /* User Interface messages from the actions */
-void ui_progress(MSIPACKAGE *, int, int, int, int);
-void ui_actiondata(MSIPACKAGE *, LPCWSTR, MSIRECORD *);
+extern void ui_progress(MSIPACKAGE *, int, int, int, int);
+extern void ui_actiondata(MSIPACKAGE *, LPCWSTR, MSIRECORD *);
 
 
 /* string consts use a number of places  and defined in helpers.c*/
@@ -279,3 +282,5 @@ extern const WCHAR cszSourceDir[];
 extern const WCHAR szProductCode[];
 extern const WCHAR cszRootDrive[];
 extern const WCHAR cszbs[];
+
+#endif /* __MSI_ACTION_H__ */