diff --git a/src/lib.rs b/src/lib.rs
index c7d1846..1487ff9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,9 +1,10 @@
 pub const M_BITS: u8 = 5;
 pub const E_BITS: u8 = 3;
-const E_MAX: u8 = 4;
+const E_CAP: u8 = 4;
 
 static_assertions::const_assert_eq!(M_BITS + E_BITS, 8);
 
+const E_MAX: u8 = E_CAP - 1;
 pub const EXACT_INT_MAX: u8 = if E_MAX > M_BITS {
 	2 << M_BITS
 } else {