diff --git a/src/sources/types.rs b/src/sources/types.rs
index 557c242..cc3c0d5 100644
--- a/src/sources/types.rs
+++ b/src/sources/types.rs
@@ -14,6 +14,8 @@ pub enum Version {
     Integer(u64),
 }
 
+// All versions are needed, even if a source is disabled at compile-time.
+#[allow(dead_code)]
 impl Version {
     /// Coarses versions into semver versions. This will use a integer version as the major
     /// field if required.