diff --git a/main.go b/main.go
index 3ae118f..7cce268 100644
--- a/main.go
+++ b/main.go
@@ -130,6 +130,8 @@ func GetMSBytes(t time.Time) ([]byte, error) {
 }
 
 var (
+	// crockfordEncodeMap takes binary values and converts them to
+	// characters in Crockford base32.
 	crockfordEncodeMap = map[uint8]rune{
 		0:  '0',
 		1:  '1',
@@ -165,22 +167,79 @@ var (
 		31: 'Z',
 	}
 
-	crockfordDecodeMap = map[rune]uint32{
+	// crockfordDecodeMap takes characters and converts them to binary
+	// values based on Crockford base32.
+	crockfordDecodeMap = map[rune]uint8{
 		'0': 0,
 		'O': 0,
 		'o': 0,
 		'1': 1,
 		'I': 1,
 		'i': 1,
+		'L': 1,
+		'l': 1,
+		'2': 2,
+		'3': 3,
+		'4': 4,
+		'5': 5,
+		'6': 6,
+		'7': 7,
+		'8': 8,
+		'9': 9,
+		'A': 10,
+		'a': 10,
+		'B': 11,
+		'b': 11,
+		'C': 12,
+		'c': 12,
+		'D': 13,
+		'd': 13,
+		'E': 14,
+		'e': 14,
+		'F': 15,
+		'f': 15,
+		'G': 16,
+		'g': 16,
+		'H': 17,
+		'h': 17,
+		'J': 18,
+		'j': 18,
+		'K': 19,
+		'k': 19,
+		'M': 20,
+		'm': 20,
+		'N': 21,
+		'n': 21,
+		'P': 22,
+		'p': 22,
+		'Q': 23,
+		'q': 23,
+		'R': 24,
+		'r': 24,
+		'S': 25,
+		's': 25,
+		'T': 26,
+		't': 26,
+		'V': 27,
+		'v': 27,
+		'W': 28,
+		'w': 28,
+		'X': 29,
+		'x': 29,
+		'Y': 30,
+		'y': 30,
+		'Z': 31,
+		'z': 31,
 	}
 )
 
-// CrockfordEncode takes a byte array and encodes every 5-bits as a
-// character string according to Crockford's base 32 encoding. This
-// specific implementation uses Big Endian byte order to fit the ULID
-// spec ("network byte ordering")
+// CrockfordEncode takes a byte array and encodes it into a character
+// string according to Crockford's base 32 encoding. Every 5-bits
+// corresponds to a character. This specific implementation uses Big
+// Endian byte order to fit the ULID spec ("network byte ordering")
 //
 // https://www.crockford.com/base32.html
+// https://git.wisellama.rocks/Mirrors/ulid-spec
 func CrockfordEncode(bytes []byte) string {
 	// Crockford is a base 32 encoding.
 	// 2^5 = 32, so every 5 bits will give us a character.