Index: trunk/pstamp/src/ppstampMakeStamp.c
===================================================================
--- trunk/pstamp/src/ppstampMakeStamp.c	(revision 20757)
+++ trunk/pstamp/src/ppstampMakeStamp.c	(revision 21160)
@@ -27,7 +27,15 @@
     // Change the reference pixel to account for the change in origin between the stamp and
     // the original image
+    // XXX: shouldn't we be using the center of the stamp instead of the corner?
     outChip->toFPA   = psPlaneTransformSetCenter(NULL, inChip->toFPA, (int) roi->x0, (int) roi->y0);
 
     outChip->fromFPA = psPlaneTransformInvert(NULL, outChip->toFPA, *roi, 50);
+
+    if (outFPA->toSky->type != PS_PROJ_TAN) {
+        if (!pmAstromLinearizeTransforms(outFPA, outChip)) {
+            psError(PS_ERR_UNKNOWN, false, "Failed to linearize astrometry\n");
+            return false;
+        }
+    }
 
     if (!pmAstromWriteWCS(outHDU->header, outFPA, outChip, WCS_NONLIN_TOL)) {