diff --git a/dlls/gdiplus/tests/pen.c b/dlls/gdiplus/tests/pen.c
index 5221423172a..3fede54d09c 100644
--- a/dlls/gdiplus/tests/pen.c
+++ b/dlls/gdiplus/tests/pen.c
@@ -133,6 +133,7 @@ static void test_dasharray(void)
     dashes[4] = 14.0;
     dashes[5] = -100.0;
     dashes[6] = -100.0;
+    dashes[7] = dashes[8] = dashes[9] = dashes[10] = dashes[11] = 0.0;
 
     /* setting the array sets the type to custom */
     GdipGetPenDashStyle(pen, &style);
@@ -173,6 +174,15 @@ static void test_dasharray(void)
     expectf(-100.0, dashes[5]);
     expectf(-100.0, dashes[6]);
 
+    /* Some invalid array values. */
+    status = GdipSetPenDashArray(pen, &dashes[7], 5);
+    todo_wine
+        expect(InvalidParameter, status);
+    dashes[9] = -1.0;
+    status = GdipSetPenDashArray(pen, &dashes[7], 5);
+    todo_wine
+        expect(InvalidParameter, status);
+
     /* Try to set with count = 0. */
     GdipSetPenDashStyle(pen, DashStyleDot);
     status = GdipSetPenDashArray(pen, dashes, 0);