diff --git a/types.go b/types.go
index 595ebcd1..bbde5bf8 100644
--- a/types.go
+++ b/types.go
@@ -1465,11 +1465,11 @@ func cmToString(mantissa, exponent uint8) string {
 func euiToString(eui uint64, bits int) (hex string) {
 	switch bits {
 	case 64:
-		hex = fmt.Sprintf("%x", eui)
+		hex = strconv.FormatUint(eui, 16)
 		hex = hex[0:1] + "-" + hex[2:3] + "-" + hex[4:5] + "-" + hex[6:7] +
 			"-" + hex[8:9] + "-" + hex[10:11] + "-" + hex[12:13] + "-" + hex[14:15]
 	case 48:
-		hex = fmt.Sprintf("%x", eui) // >> 16?
+		hex = strconv.FormatUint(eui, 16) // shift here?
 		hex = hex[0:1] + "-" + hex[2:3] + "-" + hex[4:5] + "-" + hex[6:7] +
 			"-" + hex[8:9] + "-" + hex[10:11]
 	}
diff --git a/zscan_rr.go b/zscan_rr.go
index e82e3c97..3d984174 100644
--- a/zscan_rr.go
+++ b/zscan_rr.go
@@ -1285,13 +1285,23 @@ func setEUI48(h RR_Header, c chan lex, f string) (RR, *ParseError) {
 	if len(l.token) != 17 {
 		return nil, &ParseError{f, "bad EUI48 Address", l}
 	}
+	addr := make([]byte, 12)
+	dash := 0
+	for i := 0; i < 12; i += 2 {
+		addr[i] = l.token[i+dash]
+		addr[i+1] = l.token[i+1+dash]
+		dash++
+		if l.token[i+1+dash] != '-' {
+			return nil, &ParseError{f, "bad EUI48 Address", l}
+		}
+	}
 
-	if i, e := strconv.Atoi(l.token); e != nil {
+	if i, e := strconv.ParseUint(string(addr), 16, 48); e != nil {
 		return nil, &ParseError{f, "bad EUI48 Address", l}
 	} else {
-		rr.Address = uint64(i)
+		rr.Address = i
 	}
-	return nil, nil
+	return rr, nil
 }
 
 func setEUI64(h RR_Header, c chan lex, f string) (RR, *ParseError) {
@@ -1302,13 +1312,23 @@ func setEUI64(h RR_Header, c chan lex, f string) (RR, *ParseError) {
 	if len(l.token) != 23 {
 		return nil, &ParseError{f, "bad EUI64 Address", l}
 	}
+	addr := make([]byte, 16)
+	dash := 0
+	for i := 0; i < 16; i += 2 {
+		addr[i] = l.token[i+dash]
+		addr[i+1] = l.token[i+1+dash]
+		dash++
+		if l.token[i+1+dash] != '-' {
+			return nil, &ParseError{f, "bad EUI64 Address", l}
+		}
+	}
 
-	if i, e := strconv.Atoi(l.token); e != nil {
-		return nil, &ParseError{f, "bad EUI64 Address", l}
+	if i, e := strconv.ParseUint(string(addr), 16, 64); e != nil {
+		return nil, &ParseError{f, "bad EUI68 Address", l}
 	} else {
 		rr.Address = uint64(i)
 	}
-	return nil, nil
+	return rr, nil
 }
 
 func setWKS(h RR_Header, c chan lex, f string) (RR, *ParseError, string) {