diff --git a/dlls/wineps.drv/ps.c b/dlls/wineps.drv/ps.c
index b27e9001e34..7d6fb7a1252 100644
--- a/dlls/wineps.drv/ps.c
+++ b/dlls/wineps.drv/ps.c
@@ -231,8 +231,7 @@ DWORD PSDRV_WriteSpool(PSDRV_PDEVICE *physDev, LPCSTR lpData, DWORD cch)
 }
 
 
-INT PSDRV_WriteFeature(HANDLE16 hJob, char *feature, char *value,
-			 char *invocation)
+static INT PSDRV_WriteFeature(HANDLE16 hJob, LPCSTR feature, LPCSTR value, LPSTR invocation)
 {
 
     char *buf = HeapAlloc( PSDRV_Heap, 0, sizeof(psbeginfeature) +