diff --git a/src/stdatamodels/jwst/datamodels/schemas/core.schema.yaml b/src/stdatamodels/jwst/datamodels/schemas/core.schema.yaml
index 13ae55c1..86603e09 100644
--- a/src/stdatamodels/jwst/datamodels/schemas/core.schema.yaml
+++ b/src/stdatamodels/jwst/datamodels/schemas/core.schema.yaml
@@ -2334,6 +2334,11 @@ properties:
             type: string
             fits_keyword: S_CHGMIG
             blend_table: True
+          clean_flicker_noise:
+            title: Clean flicker noise
+            type: string
+            fits_keyword: S_CLNFNS
+            blend_table: True
           combine_1d:
             title: 1-D Spectral Combination
             type: string