diff --git a/dlls/propsys/Makefile.in b/dlls/propsys/Makefile.in
index dd630b2c3a9..15637418618 100644
--- a/dlls/propsys/Makefile.in
+++ b/dlls/propsys/Makefile.in
@@ -6,7 +6,8 @@ MODULE    = propsys.dll
 IMPORTS   = kernel32
 
 C_SRCS = \
-	propsys_main.c
+	propsys_main.c \
+	propvar.c
 
 @MAKE_DLL_RULES@
 
diff --git a/dlls/propsys/propsys.spec b/dlls/propsys/propsys.spec
index 8de5e4b7b16..a2ae5222783 100644
--- a/dlls/propsys/propsys.spec
+++ b/dlls/propsys/propsys.spec
@@ -93,7 +93,7 @@
 @ stub PSSetPropertyValue
 @ stub PSStringFromPropertyKey
 @ stub PSUnregisterPropertySchema
-@ stub PropVariantChangeType
+@ stdcall PropVariantChangeType(ptr ptr long long)
 @ stub PropVariantCompareEx
 @ stub PropVariantGetBooleanElem
 @ stub PropVariantGetDoubleElem
diff --git a/dlls/propsys/propvar.c b/dlls/propsys/propvar.c
new file mode 100644
index 00000000000..cdfb89fa768
--- /dev/null
+++ b/dlls/propsys/propvar.c
@@ -0,0 +1,88 @@
+/*
+ * PropVariant implementation
+ *
+ * Copyright 2008 James Hawkins for CodeWeavers
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+
+#define NONAMELESSUNION
+
+#include "windef.h"
+#include "winbase.h"
+#include "winerror.h"
+#include "winreg.h"
+#include "winuser.h"
+#include "shlobj.h"
+#include "propvarutil.h"
+
+#include "wine/debug.h"
+
+WINE_DEFAULT_DEBUG_CHANNEL(propsys);
+
+static HRESULT PROPVAR_ConvertFILETIME(PROPVARIANT *ppropvarDest,
+                                       REFPROPVARIANT propvarSrc, VARTYPE vt)
+{
+    SYSTEMTIME time;
+
+    FileTimeToSystemTime(&propvarSrc->u.filetime, &time);
+
+    switch (vt)
+    {
+        case VT_LPSTR:
+        {
+            static const char format[] = "%04d/%02d/%02d:%02d:%02d:%02d.%03d";
+
+            ppropvarDest->u.pszVal = HeapAlloc(GetProcessHeap(), 0,
+                                             lstrlenA(format) + 1);
+            if (!ppropvarDest->u.pszVal)
+                return E_OUTOFMEMORY;
+
+            sprintf(ppropvarDest->u.pszVal, format, time.wYear, time.wMonth,
+                    time.wDay, time.wHour, time.wMinute,
+                    time.wSecond, time.wMilliseconds);
+
+            return S_OK;
+        }
+
+        default:
+            FIXME("Unhandled target type: %d\n", vt);
+    }
+
+    return E_FAIL;
+}
+
+/******************************************************************
+ *  PropVariantChangeType   (PROPSYS.@)
+ */
+HRESULT WINAPI PropVariantChangeType(PROPVARIANT *ppropvarDest, REFPROPVARIANT propvarSrc,
+                                     PROPVAR_CHANGE_FLAGS flags, VARTYPE vt)
+{
+    FIXME("(%p, %p, %d, %d, %d): semi-stub!\n", ppropvarDest, propvarSrc,
+          propvarSrc->vt, flags, vt);
+
+    switch (propvarSrc->vt)
+    {
+        case VT_FILETIME:
+            return PROPVAR_ConvertFILETIME(ppropvarDest, propvarSrc, vt);
+        default:
+            FIXME("Unhandled source type: %d\n", propvarSrc->vt);
+    }
+
+    return E_FAIL;
+}
diff --git a/include/Makefile.in b/include/Makefile.in
index 1acd285f15f..73d1cb04aab 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -326,6 +326,7 @@ SRCDIR_INCLUDES = \
 	poppack.h \
 	powrprof.h \
 	profinfo.h \
+	propvarutil.h \
 	prsht.h \
 	psapi.h \
 	pshpack1.h \
diff --git a/include/propidl.idl b/include/propidl.idl
index a0d83be267b..6720988d854 100644
--- a/include/propidl.idl
+++ b/include/propidl.idl
@@ -206,6 +206,8 @@ interface IPropertyStorage : IUnknown
 
   typedef struct tagPROPVARIANT *LPPROPVARIANT;
 
+  cpp_quote("#define REFPROPVARIANT const PROPVARIANT *")
+
   cpp_quote("#define PIDDI_THUMBNAIL 0x00000002L /* VT_BLOB */")
   cpp_quote("")
   cpp_quote("#define PIDSI_TITLE        0x00000002L /* VT_LPSTR */")
diff --git a/include/propvarutil.h b/include/propvarutil.h
new file mode 100644
index 00000000000..2573d38d1a1
--- /dev/null
+++ b/include/propvarutil.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2008 James Hawkins for CodeWeavers
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#ifndef __WINE_PROPVARUTIL_H
+#define __WINE_PROPVARUTIL_H
+
+#include <propidl.h>
+#include <shtypes.h>
+#include <shlwapi.h>
+
+enum tagPROPVAR_CHANGE_FLAGS
+{
+    PVCHF_DEFAULT           = 0x00000000,
+    PVCHF_NOVALUEPROP       = 0x00000001,
+    PVCHF_ALPHABOOL         = 0x00000002,
+    PVCHF_NOUSEROVERRIDE    = 0x00000004,
+    PVCHF_LOCALBOOL         = 0x00000008,
+    PVCHF_NOHEXSTRING       = 0x00000010,
+};
+
+typedef int PROPVAR_CHANGE_FLAGS;
+
+HRESULT WINAPI PropVariantChangeType(PROPVARIANT *ppropvarDest, REFPROPVARIANT propvarSrc,
+                                     PROPVAR_CHANGE_FLAGS flags, VARTYPE vt);
+
+#endif /* __WINE_PROPVARUTIL_H */