Index: uspace/lib/c/test/stdio.c
===================================================================
--- uspace/lib/c/test/stdio.c	(revision 9d8307a94aa6d903e4fcaa8ae5c22e2fa48fddfb)
+++ uspace/lib/c/test/stdio.c	(revision 0abc2aea144199fee5fb2b5b1ffcf9f0ac6528ce)
@@ -62,5 +62,5 @@
 	PCUT_ASSERT_TRUE(rc != 0);
 
-	f = fopen(buf, "w");
+	f = fopen(buf, "wx");
 	PCUT_ASSERT_NOT_NULL(f);
 	fclose(f);
@@ -92,5 +92,5 @@
 	PCUT_ASSERT_NOT_NULL(p);
 
-	f = fopen(buf1, "w");
+	f = fopen(buf1, "wx");
 	PCUT_ASSERT_NOT_NULL(f);
 	fclose(f);
@@ -142,5 +142,5 @@
 	PCUT_ASSERT_NOT_NULL(p);
 
-	f = fopen(p, "w+");
+	f = fopen(p, "w+x");
 	PCUT_ASSERT_NOT_NULL(f);
 	(void) remove(p);
@@ -174,5 +174,5 @@
 	PCUT_ASSERT_NOT_NULL(p);
 
-	f = fopen(p, "w+");
+	f = fopen(p, "w+x");
 	PCUT_ASSERT_NOT_NULL(f);
 	(void) remove(p);