--- a/src/extract.c
+++ b/src/extract.c
@@ -1056,10 +1056,8 @@
 PURPOSE	initialize a pixel-list and its components.
  ***/
 void plistinit(int hasconv, int hasvar) {
-  pbliststruct * pbdum = NULL;
-
   plistsize = sizeof(pbliststruct);
-  plistoff_value = (char *)&pbdum->value - (char *)pbdum;
+  plistoff_value = offsetof(pbliststruct, value);
 
   if (hasconv) {
     plistexist_cdvalue = 1;
@@ -1082,6 +1080,9 @@
     plistexist_var = 0;
     plistexist_thresh = 0;
   }
+  /* Stellastack: appended float fields must not misalign the next record. */
+  const size_t alignment = _Alignof(pbliststruct);
+  plistsize = ((plistsize + alignment - 1) / alignment) * alignment;
 }
 
 
@@ -1293,8 +1294,6 @@
   QMALLOC(cat->ycpeak, int64_t, nobj, status);
   QMALLOC(cat->xpeak, int64_t, nobj, status);
   QMALLOC(cat->ypeak, int64_t, nobj, status);
-  QMALLOC(cat->cflux, float, nobj, status);
-  QMALLOC(cat->flux, float, nobj, status);
   QMALLOC(cat->flag, short, nobj, status);
 
   /* fill output arrays */