diff --git a/version/src/lib.rs b/version/src/lib.rs
index b94683d89c..142266675b 100644
--- a/version/src/lib.rs
+++ b/version/src/lib.rs
@@ -11,14 +11,22 @@ pub struct Version {
     commit: Option<u32>, // first 4 bytes of the sha1 commit hash
 }
 
+fn compute_commit(sha1: Option<&'static str>) -> Option<u32> {
+    let sha1 = sha1?;
+    if sha1.len() < 8 {
+        None
+    } else {
+        u32::from_str_radix(&sha1[..8], 16).ok()
+    }
+}
+
 impl Default for Version {
     fn default() -> Self {
         Self {
             major: env!("CARGO_PKG_VERSION_MAJOR").parse().unwrap(),
             minor: env!("CARGO_PKG_VERSION_MINOR").parse().unwrap(),
             patch: env!("CARGO_PKG_VERSION_PATCH").parse().unwrap(),
-            commit: option_env!("CI_COMMIT")
-                .map(|sha1| u32::from_str_radix(&sha1[..8], 16).unwrap()),
+            commit: compute_commit(option_env!("CI_COMMIT")),
         }
     }
 }
@@ -47,3 +55,16 @@ macro_rules! version {
         &*format!("{}", $crate::Version::default())
     };
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_compute_commit() {
+        assert_eq!(compute_commit(None), None);
+        assert_eq!(compute_commit(Some("1234567890")), Some(0x12345678));
+        assert_eq!(compute_commit(Some("HEAD")), None);
+        assert_eq!(compute_commit(Some("garbagein")), None);
+    }
+}