diff --git a/lib/pembase64.c b/lib/pembase64.c
index fe70aab..6b5393f 100644
--- a/lib/pembase64.c
+++ b/lib/pembase64.c
@@ -378,8 +378,7 @@
     if (ctx->certificates.list == NULL) {
         ret = PTLS_ERROR_NO_MEMORY;
     } else {
-        ret = ptls_load_pem_objects(cert_pem_file, "PUBLIC KEY", ctx->certificates.list, PTLS_MAX_CERTS_IN_CONTEXT,
-                                    &ctx->certificates.count);
+        ret = ptls_load_pem_objects(cert_pem_file, "PUBLIC KEY", ctx->certificates.list, 1, &ctx->certificates.count);
     }
 
     return ret;