diff --git a/ext/openssl/extconf.rb b/ext/openssl/extconf.rb
index 0dc1a5eb4..ada1f3f81 100644
--- a/ext/openssl/extconf.rb
+++ b/ext/openssl/extconf.rb
@@ -176,13 +176,16 @@ def find_openssl_library
 have_func("TS_STATUS_INFO_get0_status")
 have_func("TS_STATUS_INFO_get0_text")
 have_func("TS_STATUS_INFO_get0_failure_info")
-have_func("TS_VERIFY_CTS_set_certs")
+have_func("TS_VERIFY_CTS_set_certs(NULL, NULL)", "openssl/ts.h")
 have_func("TS_VERIFY_CTX_set_store")
 have_func("TS_VERIFY_CTX_add_flags")
 have_func("TS_RESP_CTX_set_time_cb")
 have_func("EVP_PBE_scrypt")
 have_func("SSL_CTX_set_post_handshake_auth")
 
+# added in 3.0.0
+have_func("TS_VERIFY_CTX_set_certs(NULL, NULL)", "openssl/ts.h")
+
 Logging::message "=== Checking done. ===\n"
 
 create_header
diff --git a/ext/openssl/openssl_missing.h b/ext/openssl/openssl_missing.h
index 7d218f86f..42b3cca5b 100644
--- a/ext/openssl/openssl_missing.h
+++ b/ext/openssl/openssl_missing.h
@@ -254,4 +254,9 @@ IMPL_PKEY_GETTER(EC_KEY, ec)
     } while (0)
 #endif
 
+/* added in 3.0.0 */
+#if !defined(HAVE_TS_VERIFY_CTX_SET_CERTS)
+#  define TS_VERIFY_CTX_set_certs(ctx, crts) TS_VERIFY_CTS_set_certs(ctx, crts)
+#endif
+
 #endif /* _OSSL_OPENSSL_MISSING_H_ */
diff --git a/ext/openssl/ossl_ts.c b/ext/openssl/ossl_ts.c
index cff9b7bff..821741553 100644
--- a/ext/openssl/ossl_ts.c
+++ b/ext/openssl/ossl_ts.c
@@ -820,7 +820,7 @@ ossl_ts_resp_verify(int argc, VALUE *argv, VALUE self)
         X509_up_ref(cert);
     }
 
-    TS_VERIFY_CTS_set_certs(ctx, x509inter);
+    TS_VERIFY_CTX_set_certs(ctx, x509inter);
     TS_VERIFY_CTX_add_flags(ctx, TS_VFY_SIGNATURE);
     TS_VERIFY_CTX_set_store(ctx, x509st);