diff --git a/src/drivers/bus/isapnp.c b/src/drivers/bus/isapnp.c
index a19beb80..7903208d 100644
--- a/src/drivers/bus/isapnp.c
+++ b/src/drivers/bus/isapnp.c
@@ -653,11 +653,12 @@ static int isapnpbus_probe ( struct root_device *rootdev ) {
 
 			/* Allocate struct isapnp_device */
 			if ( ! isapnp )
-				isapnp = zalloc ( sizeof ( *isapnp ) );
+				isapnp = malloc ( sizeof ( *isapnp ) );
 			if ( ! isapnp ) {
 				rc = -ENOMEM;
 				goto err;
 			}
+			memset ( isapnp, 0, sizeof ( *isapnp ) );
 			isapnp->csn = csn;
 			isapnp->logdev = logdev;