diff --git a/dlls/gdiplus/font.c b/dlls/gdiplus/font.c
index 1068a478004..ccf93ed395a 100644
--- a/dlls/gdiplus/font.c
+++ b/dlls/gdiplus/font.c
@@ -558,6 +558,8 @@ GpStatus WINGDIPAPI GdipGetFontHeight(GDIPCONST GpFont *font,
 
     TRACE("%p %p %p\n", font, graphics, height);
 
+    if (!font || !height) return InvalidParameter;
+
     stat = GdipGetFontHeightGivenDPI(font, font->family->dpi, &font_height);
     if (stat != Ok) return stat;