diff --git a/parser_test.go b/parser_test.go
index 986279e..4232059 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -14,7 +14,15 @@ func Todo(t *testing.T) {
 	t.Errorf("TODO")
 }
 
-func notP[T any](pred func(T) bool) func(T) bool {
+func curry[A, B, C any](f func(A, B) C) func(A) func(B) C {
+	return func(a A) func(B) C {
+		return func(b B) C {
+			return f(a, b)
+		}
+	}
+}
+
+func not[T any](pred func(T) bool) func(T) bool {
 	return func(x T) bool { return !pred(x) }
 }
 
@@ -39,7 +47,7 @@ func TestSlice(t *testing.T) {
 	t.Run("fails with wrong contents", rapid.MakeCheck(func(t *rapid.T) {
 		s := rapid.SliceOfN(rapid.Byte(), 1, -1).Draw(t, "s")
 		input := rapid.SliceOfN(rapid.Byte(), len(s), -1).
-			Filter(notP(hasPrefix(s))).Draw(t, "input")
+			Filter(not(curry(bytes.HasPrefix)(s))).Draw(t, "input")
 		assertParseFails(t, input, gigaparsec.Slice(s))
 	}))
 	t.Run("fails at end of input", rapid.MakeCheck(func(t *rapid.T) {