--- a/tests/QC/ByteString.hs
+++ b/tests/QC/ByteString.hs
@@ -166,7 +166,7 @@
     , testProperty "peekWord8" peekWord8
     , testProperty "peekWord8'" peekWord8'
     , testProperty "satisfy" satisfy
-    , testProperty "satisfyWith" satisfyWith
+    , testProperty "satisfyWith" (forAll arbitraryASCIIChar satisfyWith)
     , testProperty "scan" scan
     , testProperty "skip" skip
     , testProperty "skipWhile" skipWhile
