diff --git a/programs/x509/cert_write.c b/programs/x509/cert_write.c
index e50a99d..8f0616c 100644
--- a/programs/x509/cert_write.c
+++ b/programs/x509/cert_write.c
@@ -652,6 +652,7 @@
     pk_free( &loaded_subject_key );
     pk_free( &loaded_issuer_key );
     mpi_free( &serial );
+    ctr_drbg_free( &ctr_drbg );
     entropy_free( &entropy );
 
 #if defined(_WIN32)