diff --git a/src/lib.rs b/src/lib.rs
index e1bf172..58c0a4d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -190,8 +190,8 @@ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         );
         debug_assert!(err == 1);
     }
-    for ch in &v[..] {
-        write!(f, "{:02x}", *ch)?;
+    for i in 0..len {
+        write!(f, "{:02x}", v[i])?;
     }
     Ok(())
 }
@@ -400,7 +400,12 @@ impl From<ffi::Signature> for Signature {
 #[cfg(feature = "serde")]
 impl ::serde::Serialize for Signature {
     fn serialize<S: ::serde::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
-        s.serialize_bytes(&self.serialize_der())
+        if s.is_human_readable() {
+            s.collect_str(self)
+        } else {
+            s.serialize_bytes(&self.serialize_der())
+        }
+
     }
 }
 
@@ -408,9 +413,14 @@ impl ::serde::Serialize for Signature {
 impl<'de> ::serde::Deserialize<'de> for Signature {
     fn deserialize<D: ::serde::Deserializer<'de>>(d: D) -> Result<Signature, D::Error> {
         use ::serde::de::Error;
-
-        let sl: &[u8] = ::serde::Deserialize::deserialize(d)?;
-        Signature::from_der(sl).map_err(D::Error::custom)
+        use str::FromStr;
+        if d.is_human_readable() {
+            let sl: &str = ::serde::Deserialize::deserialize(d)?;
+            Signature::from_str(sl).map_err(D::Error::custom)
+        } else {
+            let sl: &[u8] = ::serde::Deserialize::deserialize(d)?;
+            Signature::from_der(sl).map_err(D::Error::custom)
+        }
     }
 }
 
@@ -840,6 +850,11 @@ mod tests {
              72022100e89bd46bb3a5a62adc679f659b7ce876d83ee297c7a5587b2011c4fcc72eab45\
              72022100e89bd46bb3a5a62adc679f659b7ce876d83ee297c7a5587b2011c4fcc72eab45"
         ).is_err());
+
+        // 71 byte signature
+        let hex_str = "30450221009d0bad576719d32ae76bedb34c774866673cbde3f4e12951555c9408e6ce774b02202876e7102f204f6bfee26c967c3926ce702cf97d4b010062e193f763190f6776";
+        let sig = Signature::from_str(&hex_str).expect("byte str decode");
+        assert_eq!(&format!("{}", sig), hex_str);
     }
 
     #[test]
@@ -966,7 +981,7 @@ mod tests {
     #[cfg(feature = "serde")]
     #[test]
     fn test_signature_serde() {
-        use serde_test::{Token, assert_tokens};
+        use serde_test::{Configure, Token, assert_tokens};
 
         let s = Secp256k1::new();
 
@@ -980,8 +995,13 @@ mod tests {
             226, 108, 150, 124, 57, 38, 206, 112, 44, 249, 125, 75, 1, 0, 98, 225,
             147, 247, 99, 25, 15, 103, 118
         ];
+        static SIG_STR: &'static str = "\
+            30450221009d0bad576719d32ae76bedb34c774866673cbde3f4e12951555c9408e6ce77\
+            4b02202876e7102f204f6bfee26c967c3926ce702cf97d4b010062e193f763190f6776\
+        ";
 
-        assert_tokens(&sig, &[Token::BorrowedBytes(&SIG_BYTES[..])]);
+        assert_tokens(&sig.compact(), &[Token::BorrowedBytes(&SIG_BYTES[..])]);
+        assert_tokens(&sig.readable(), &[Token::BorrowedStr(SIG_STR)]);
     }
 }