diff --git a/reactos/dll/win32/setupapi/diskspace.c b/reactos/dll/win32/setupapi/diskspace.c
index 7ed6217f6a3..32b80fb1d7f 100644
--- a/reactos/dll/win32/setupapi/diskspace.c
+++ b/reactos/dll/win32/setupapi/diskspace.c
@@ -248,3 +248,27 @@ BOOL WINAPI SetupDestroyDiskSpaceList(HDSKSPC DiskSpace)
     HeapFree(GetProcessHeap(),0,list);
     return TRUE;
 }
+
+/***********************************************************************
+*		SetupAddToDiskSpaceListA  (SETUPAPI.@)
+*/
+BOOL WINAPI SetupAddToDiskSpaceListA(HDSKSPC diskspace, PCSTR targetfile,
+                                    LONGLONG filesize, UINT operation,
+                                    PVOID reserved1, UINT reserved2)
+{
+    FIXME(": stub\n");
+    SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
+    return FALSE;
+}
+
+/***********************************************************************
+*		SetupAddToDiskSpaceListW  (SETUPAPI.@)
+*/
+BOOL WINAPI SetupAddToDiskSpaceListW(HDSKSPC diskspace, PCWSTR targetfile,
+                                    LONGLONG filesize, UINT operation,
+                                    PVOID reserved1, UINT reserved2)
+{
+    FIXME(": stub\n");
+    SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
+    return FALSE;
+}
diff --git a/reactos/dll/win32/setupapi/setupapi.spec b/reactos/dll/win32/setupapi/setupapi.spec
index 7de1d290d75..ffe81c4bb4f 100644
--- a/reactos/dll/win32/setupapi/setupapi.spec
+++ b/reactos/dll/win32/setupapi/setupapi.spec
@@ -221,8 +221,8 @@
 @ stub SetupAddInstallSectionToDiskSpaceListW
 @ stdcall -stub SetupAddSectionToDiskSpaceListA(long long long str long ptr long)
 @ stub SetupAddSectionToDiskSpaceListW
-@ stdcall -stub SetupAddToDiskSpaceListA(long str double long ptr long)
-@ stub SetupAddToDiskSpaceListW
+@ stdcall SetupAddToDiskSpaceListA(long str int64 long ptr long)
+@ stdcall SetupAddToDiskSpaceListW(long wstr int64 long ptr long)
 @ stub SetupAddToSourceListA
 @ stub SetupAddToSourceListW
 @ stub SetupAdjustDiskSpaceListA