diff --git a/modules/deeplearning/srcnn_l1b_l2.py b/modules/deeplearning/srcnn_l1b_l2.py
index e845ebf656379ab26eef24fbf5c97824dd3555b6..801a0914545427eb1798df28c07b3ac86a490a68 100644
--- a/modules/deeplearning/srcnn_l1b_l2.py
+++ b/modules/deeplearning/srcnn_l1b_l2.py
@@ -774,7 +774,7 @@ def analyze(fpath='/Users/tomrink/clavrx_snpp_viirs.A2019080.0100.001.2019080064
     print(grd_lr.shape)
     leny, lenx = grd_lr.shape
     rnd = np.random.normal(loc=0, scale=0.001, size=grd_lr.size)
-    grd_lr += rnd.reshape(grd_lr.shape)
+    grd_lr = grd_lr + rnd.reshape(grd_lr.shape)
     if param == 'cloud_fraction':
         grd_lr = np.where(grd_lr < 0, 0, grd_lr)
         grd_lr = np.where(grd_lr > 1, 1, grd_lr)