diff --git a/openssl-sys/build/main.rs b/openssl-sys/build/main.rs
index a1f163d7..02b93b90 100644
--- a/openssl-sys/build/main.rs
+++ b/openssl-sys/build/main.rs
@@ -247,6 +247,7 @@ due to this version mismatch.
 }
 
 // parses a string that looks like "0x100020cfL"
+#[allow(deprecated)] // trim_right_matches is now trim_end_matches
 fn parse_version(version: &str) -> u64 {
     // cut off the 0x prefix
     assert!(version.starts_with("0x"));