diff --git a/src/scitokens_internal.cpp b/src/scitokens_internal.cpp
index 0b37773..990d43d 100644
--- a/src/scitokens_internal.cpp
+++ b/src/scitokens_internal.cpp
@@ -532,6 +532,8 @@ std::string rs256_from_coords(const std::string &e_str,
         throw UnsupportedKeyException("Failed to serialize RSA public key");
     }
 #endif
+    e_bignum.release();
+    n_bignum.release();
 
     char *mem_data;
     size_t mem_len = BIO_get_mem_data(pubkey_bio.get(), &mem_data);