Index: trunk/ppSub/src/ppSubReadout.c
===================================================================
--- trunk/ppSub/src/ppSubReadout.c	(revision 20492)
+++ trunk/ppSub/src/ppSubReadout.c	(revision 20506)
@@ -93,4 +93,5 @@
     int iter = psMetadataLookupS32(NULL, recipe, "ITER"); // Rejection iterations
     float rej = psMetadataLookupF32(NULL, recipe, "REJ"); // Rejection threshold
+    float sys = psMetadataLookupF32(NULL, recipe, "SYS"); // Relative systematic error in kernel
     bool reverse = psMetadataLookupBool(NULL, config->arguments, "REVERSE"); // Reverse sense of subtraction?
     psVector *widths = psMetadataLookupPtr(NULL, recipe, "ISIS.WIDTHS"); // ISIS Gaussian widths
@@ -181,5 +182,5 @@
     if (!pmSubtractionMatch(inConv, refConv, inRO, refRO, footprint, regionSize, spacing, threshold, sources,
                             stampsName, type, size, order, widths, orders, inner, ringsOrder, binning,
-                            penalty, optimum, optWidths, optOrder, optThresh, iter, rej, maskVal,
+                            penalty, optimum, optWidths, optOrder, optThresh, iter, rej, sys, maskVal,
                             maskBad, maskPoor, poorFrac, badFrac, subMode)) {
         psError(PS_ERR_UNKNOWN, false, "Unable to match images.");