diff --git a/btcec/signature.go b/btcec/signature.go
index fedd92e9..92929c7d 100644
--- a/btcec/signature.go
+++ b/btcec/signature.go
@@ -85,6 +85,11 @@ func (sig *Signature) IsEqual(otherSig *Signature) bool {
 		sig.S.Cmp(otherSig.S) == 0
 }
 
+// minSigLen is the minimum length of a DER encoded signature and is
+// when both R and S are 1 byte each.
+// 0x30 + <1-byte> + 0x02 + 0x01 + <byte> + 0x2 + 0x01 + <byte>
+const minSigLen = 8
+
 func parseSig(sigStr []byte, curve elliptic.Curve, der bool) (*Signature, error) {
 	// Originally this code used encoding/asn1 in order to parse the
 	// signature, but a number of problems were found with this approach.
@@ -98,9 +103,7 @@ func parseSig(sigStr []byte, curve elliptic.Curve, der bool) (*Signature, error)
 
 	signature := &Signature{}
 
-	// minimal message is when both numbers are 1 bytes. adding up to:
-	// 0x30 + len + 0x02 + 0x01 + <byte> + 0x2 + 0x01 + <byte>
-	if len(sigStr) < 8 {
+	if len(sigStr) < minSigLen {
 		return nil, errors.New("malformed signature: too short")
 	}
 	// 0x30
@@ -115,7 +118,7 @@ func parseSig(sigStr []byte, curve elliptic.Curve, der bool) (*Signature, error)
 
 	// siglen should be less than the entire message and greater than
 	// the minimal message of size 8.
-	if int(siglen+2) > len(sigStr) || int(siglen+2) < 8 {
+	if int(siglen+2) > len(sigStr) || int(siglen+2) < minSigLen {
 		return nil, errors.New("malformed signature: bad length")
 	}
 	// trim the slice we're working on so we only look at what matters.