diff --git a/agent/pksign.c b/agent/pksign.c
index 9147b50d0..0160a11f1 100644
--- a/agent/pksign.c
+++ b/agent/pksign.c
@@ -62,13 +62,15 @@ do_encode_md (const byte * md, size_t mdlen, int algo, gcry_sexp_t * r_hash,
       gcry_mpi_t mpi;
 
       rc = gcry_mpi_scan (&mpi, GCRYMPI_FMT_USG, md, mdlen, NULL);
-      if (! rc)
+      if (!rc)
 	{
 	  rc = gcry_sexp_build (&hash, NULL,
 				"(data (flags raw) (value %m))",
 				mpi);
 	  gcry_mpi_release (mpi);
 	}
+      else
+        hash = NULL;
 
     }