diff --git a/drizzlepac/haputils/processing_utils.py b/drizzlepac/haputils/processing_utils.py
index c2b1f158f..eeecbfce1 100644
--- a/drizzlepac/haputils/processing_utils.py
+++ b/drizzlepac/haputils/processing_utils.py
@@ -169,6 +169,11 @@ def refine_product_headers(product, total_obj_list):
     # Re-format ACS filter specification
     if phdu['instrume'] == 'ACS':
         phdu['filter'] = get_acs_filters(hdu, delimiter=';')
+        
+    # WFPC2 update aperture if in poller file
+    if total_obj_list[0].aperture != 'empty_aperture':
+        log.info(f"Updating aperture header keyword from {phdu['aperture']} to {total_obj_list[0].aperture}")
+        phdu['aperture'] = total_obj_list[0].aperture
 
     # Insure PHOT* keywords are always in SCI extension
     for pkw in PHOT_KEYWORDS: