diff --git a/programs/pkey/dh_genprime.c b/programs/pkey/dh_genprime.c
index e75b338..598940e 100644
--- a/programs/pkey/dh_genprime.c
+++ b/programs/pkey/dh_genprime.c
@@ -154,6 +154,7 @@
 exit:
 
     mpi_free( &G ); mpi_free( &P ); mpi_free( &Q );
+    ctr_drbg_free( &ctr_drbg );
     entropy_free( &entropy );
 
 #if defined(_WIN32)