Index: trunk/psphot/src/psphotSubtractBackground.c
===================================================================
--- trunk/psphot/src/psphotSubtractBackground.c	(revision 20453)
+++ trunk/psphot/src/psphotSubtractBackground.c	(revision 21183)
@@ -28,5 +28,5 @@
 
     // user-defined masks to test for good/bad pixels (build from recipe list if not yet set)
-    psMaskType maskVal = psMetadataLookupU8(&status, recipe, "MASK.PSPHOT"); // Mask value for bad pixels
+    psImageMaskType maskVal = psMetadataLookupImageMask(&status, recipe, "MASK.PSPHOT"); // Mask value for bad pixels
     assert (maskVal);