diff --git a/crypto/bn/exponentiation.c b/crypto/bn/exponentiation.c
index 3a077048..57f319ae 100644
--- a/crypto/bn/exponentiation.c
+++ b/crypto/bn/exponentiation.c
@@ -172,12 +172,13 @@ int BN_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx) {
       }
     }
   }
-  ret = 1;
 
-err:
   if (r != rr) {
     BN_copy(r, rr);
   }
+  ret = 1;
+
+err:
   BN_CTX_end(ctx);
   return ret;
 }