diff --git a/ch04.asciidoc b/ch04.asciidoc
index ef64d8b6..cec785eb 100644
--- a/ch04.asciidoc
+++ b/ch04.asciidoc
@@ -582,7 +582,7 @@ Table 4-5 shows the relationship between the size of entropy data and the length
 .Mnemonic codes: entropy and word length
 [options="header"]
 |=======
-|Entropy (bits) | Checksum (bits) | Entropy+Checksum | Word Length
+|Entropy (bits) | Checksum (bits) | Entropy+checksum | Word length
 | 128 | 4 | 132 | 12
 | 160 | 5 | 165 | 15
 | 192 | 6 | 198 | 18