diff --git a/openssl-sys/build/cfgs.rs b/openssl-sys/build/cfgs.rs
index cc13b2802e548cf16497b77207d04e21e0ffb2d7..c1d9ddd5a62669069b6af1ed340f8048dcaf4810 100644
--- a/openssl-sys/build/cfgs.rs
+++ b/openssl-sys/build/cfgs.rs
@@ -34,6 +34,9 @@ pub fn get(openssl_version: Option<u64>, libressl_version: Option<u64>) -> Vec<&
         if libressl_version >= 0x3_03_02_00_0 {
             cfgs.push("libressl332");
         }
+        if libressl_version >= 0x3_04_00_00_0 {
+            cfgs.push("libressl340");
+        }
         if libressl_version >= 0x3_05_00_00_0 {
             cfgs.push("libressl350");
         }