diff --git a/parse_test.go b/parse_test.go
index f819199d56efd9e440a0543d5e5789cc22ce91f1..242d582eead1bae14f72a340a55ab96ab5dab935 100644
--- a/parse_test.go
+++ b/parse_test.go
@@ -2,35 +2,79 @@ package chunk
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 )
 
+const (
+	testTwoThirdsOfBlockPayloadLimit = 2 * (float32(BlockPayloadLimit) / float32(3))
+)
+
 func TestParseRabin(t *testing.T) {
-	max := 1000
-	r := bytes.NewReader(randBuf(t, max))
-	chk1 := "rabin-18-25-32"
-	chk2 := "rabin-15-23-31"
-	_, err := parseRabinString(r, chk1)
+	r := bytes.NewReader(randBuf(t, 1000))
+
+	_, err := FromString(r, "rabin-18-25-32")
 	if err != nil {
 		t.Errorf(err.Error())
 	}
-	_, err = parseRabinString(r, chk2)
+
+	_, err = FromString(r, "rabin-15-23-31")
 	if err != ErrRabinMin {
 		t.Fatalf("Expected an 'ErrRabinMin' error, got: %#v", err)
 	}
+
+	_, err = FromString(r, "rabin-20-20-21")
+	if err == nil || err.Error() != "incorrect format: rabin-min must be smaller than rabin-avg" {
+		t.Fatalf("Expected an arg-out-of-order error, got: %#v", err)
+	}
+
+	_, err = FromString(r, "rabin-19-21-21")
+	if err == nil || err.Error() != "incorrect format: rabin-avg must be smaller than rabin-max" {
+		t.Fatalf("Expected an arg-out-of-order error, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("rabin-19-21-%d", BlockPayloadLimit))
+	if err != nil {
+		t.Fatalf("Expected success, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("rabin-19-21-%d", 1+BlockPayloadLimit))
+	if err != ErrSizeMax {
+		t.Fatalf("Expected 'ErrSizeMax', got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("rabin-%.0f", testTwoThirdsOfBlockPayloadLimit))
+	if err != nil {
+		t.Fatalf("Expected success, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("rabin-%.0f", 1+testTwoThirdsOfBlockPayloadLimit))
+	if err != ErrSizeMax {
+		t.Fatalf("Expected 'ErrSizeMax', got: %#v", err)
+	}
+
 }
 
 func TestParseSize(t *testing.T) {
-	max := 1000
-	r := bytes.NewReader(randBuf(t, max))
-	size1 := "size-0"
-	size2 := "size-32"
-	_, err := FromString(r, size1)
+	r := bytes.NewReader(randBuf(t, 1000))
+
+	_, err := FromString(r, "size-0")
 	if err != ErrSize {
 		t.Fatalf("Expected an 'ErrSize' error, got: %#v", err)
 	}
-	_, err = FromString(r, size2)
+
+	_, err = FromString(r, "size-32")
+	if err != nil {
+		t.Fatalf("Expected success, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("size-%d", BlockPayloadLimit))
 	if err != nil {
-		t.Fatal(err)
+		t.Fatalf("Expected success, got: %#v", err)
+	}
+
+	_, err = FromString(r, fmt.Sprintf("size-%d", 1+BlockPayloadLimit))
+	if err != ErrSizeMax {
+		t.Fatalf("Expected 'ErrSizeMax', got: %#v", err)
 	}
 }