diff --git a/lib/des/rsa.h b/lib/des/rsa.h
index 98c320153..829781314 100644
--- a/lib/des/rsa.h
+++ b/lib/des/rsa.h
@@ -40,6 +40,7 @@
 
 /* symbol renaming */
 #define RSA_null_method hc_RSA_null_method
+#define RSA_imath_method hc_RSA_imath_method
 #define RSA_new hc_RSA_new
 #define RSA_new_method hc_RSA_new_method
 #define RSA_free hc_RSA_free
@@ -128,6 +129,7 @@ struct RSA {
  */
 
 const RSA_METHOD *RSA_null_method(void);
+const RSA_METHOD *RSA_imath_method(void);
 
 /*
  *