diff --git a/lib/constants.py b/lib/constants.py
index af3df19d0728b2a4a0c08b8aa237dd87fbcaa45b..5187c99934e1326ab763036f4b9063153290cd8d 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -974,7 +974,7 @@ ND_OOB_PROGRAM = "oob_program"
 ND_SPINDLE_COUNT = "spindle_count"
 
 NDS_PARAMETER_TYPES = {
-  ND_OOB_PROGRAM: VTYPE_MAYBE_STRING,
+  ND_OOB_PROGRAM: VTYPE_STRING,
   ND_SPINDLE_COUNT: VTYPE_INT,
   }
 
@@ -1842,7 +1842,7 @@ BEC_DEFAULTS = {
   }
 
 NDC_DEFAULTS = {
-  ND_OOB_PROGRAM: None,
+  ND_OOB_PROGRAM: "",
   ND_SPINDLE_COUNT: 1,
   }
 
diff --git a/lib/objects.py b/lib/objects.py
index 74526d338235373a10da51d4e353d1f1aaad01b8..a852593e463c8c4a85808f891844d7e87520bacb 100644
--- a/lib/objects.py
+++ b/lib/objects.py
@@ -173,6 +173,10 @@ def UpgradeNDParams(ndparams):
   if ndparams is None:
     ndparams = {}
 
+  if (constants.ND_OOB_PROGRAM in ndparams and
+      ndparams[constants.ND_OOB_PROGRAM] is None):
+    # will be reset by the line below
+    del ndparams[constants.ND_OOB_PROGRAM]
   return FillDict(constants.NDC_DEFAULTS, ndparams)