diff --git a/include/openssl/opensslconf.h b/include/openssl/opensslconf.h
index 5165703..feb9246 100644
--- a/include/openssl/opensslconf.h
+++ b/include/openssl/opensslconf.h
@@ -18,6 +18,7 @@
 #ifndef OPENSSL_HEADER_OPENSSLCONF_H
 #define OPENSSL_HEADER_OPENSSLCONF_H
 
+/* Keep in sync with the list in rust/bssl-sys/build.rs */
 
 #define OPENSSL_NO_ASYNC
 #define OPENSSL_NO_BF
diff --git a/rust/bssl-sys/Cargo.toml b/rust/bssl-sys/Cargo.toml
index 634ed3c..b01979a 100644
--- a/rust/bssl-sys/Cargo.toml
+++ b/rust/bssl-sys/Cargo.toml
@@ -5,3 +5,7 @@
 edition = "2018"
 publish = false
 license = "MIT"
+
+# This exists to workaround a limitation in cargo:
+# https://github.com/rust-lang/cargo/issues/3544
+links = "bssl"
diff --git a/rust/bssl-sys/build.rs b/rust/bssl-sys/build.rs
index 2d7461a..91a9f8a 100644
--- a/rust/bssl-sys/build.rs
+++ b/rust/bssl-sys/build.rs
@@ -17,6 +17,57 @@
 use std::path::Path;
 use std::path::PathBuf;
 
+// Keep in sync with the list in include/openssl/opensslconf.h
+const OSSL_CONF_DEFINES: &[&str] = &[
+    "OPENSSL_NO_ASYNC",
+    "OPENSSL_NO_BF",
+    "OPENSSL_NO_BLAKE2",
+    "OPENSSL_NO_BUF_FREELISTS",
+    "OPENSSL_NO_CAMELLIA",
+    "OPENSSL_NO_CAPIENG",
+    "OPENSSL_NO_CAST",
+    "OPENSSL_NO_CMS",
+    "OPENSSL_NO_COMP",
+    "OPENSSL_NO_CT",
+    "OPENSSL_NO_DANE",
+    "OPENSSL_NO_DEPRECATED",
+    "OPENSSL_NO_DGRAM",
+    "OPENSSL_NO_DYNAMIC_ENGINE",
+    "OPENSSL_NO_EC_NISTP_64_GCC_128",
+    "OPENSSL_NO_EC2M",
+    "OPENSSL_NO_EGD",
+    "OPENSSL_NO_ENGINE",
+    "OPENSSL_NO_GMP",
+    "OPENSSL_NO_GOST",
+    "OPENSSL_NO_HEARTBEATS",
+    "OPENSSL_NO_HW",
+    "OPENSSL_NO_IDEA",
+    "OPENSSL_NO_JPAKE",
+    "OPENSSL_NO_KRB5",
+    "OPENSSL_NO_MD2",
+    "OPENSSL_NO_MDC2",
+    "OPENSSL_NO_OCB",
+    "OPENSSL_NO_OCSP",
+    "OPENSSL_NO_RC2",
+    "OPENSSL_NO_RC5",
+    "OPENSSL_NO_RFC3779",
+    "OPENSSL_NO_RIPEMD",
+    "OPENSSL_NO_RMD160",
+    "OPENSSL_NO_SCTP",
+    "OPENSSL_NO_SEED",
+    "OPENSSL_NO_SM2",
+    "OPENSSL_NO_SM3",
+    "OPENSSL_NO_SM4",
+    "OPENSSL_NO_SRP",
+    "OPENSSL_NO_SSL_TRACE",
+    "OPENSSL_NO_SSL2",
+    "OPENSSL_NO_SSL3",
+    "OPENSSL_NO_SSL3_METHOD",
+    "OPENSSL_NO_STATIC_ENGINE",
+    "OPENSSL_NO_STORE",
+    "OPENSSL_NO_WHIRLPOOL",
+];
+
 fn get_bssl_build_dir() -> PathBuf {
     println!("cargo:rerun-if-env-changed=BORINGSSL_BUILD_DIR");
     if let Some(build_dir) = env::var_os("BORINGSSL_BUILD_DIR") {
@@ -54,4 +105,6 @@
         bssl_sys_build_dir.display()
     );
     println!("cargo:rustc-link-lib=static=rust_wrapper");
+
+    println!("cargo:conf={}", OSSL_CONF_DEFINES.join(","));
 }