diff --git a/src/board.rs b/src/board.rs
index 8e12050..85b4ff4 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -128,7 +128,7 @@ impl File {
 
     #[inline]
     pub fn from_char(file: char) -> Option<Self> {
-        Self::from_ascii(file as u8)
+        Some(Self::from_ascii(u8::try_from(file).ok()?)?)
     }
 
     #[inline]
@@ -208,7 +208,7 @@ impl Rank {
 
     #[inline]
     pub fn from_char(rank: char) -> Option<Self> {
-        Self::from_ascii(rank as u8)
+        Some(Self::from_ascii(u8::try_from(rank).ok()?)?)
     }
 
     #[inline]