diff --git a/py4DSTEM/process/diffraction/WK_scattering_factors.py b/py4DSTEM/process/diffraction/WK_scattering_factors.py
index eb964de96..23bb5c5d3 100644
--- a/py4DSTEM/process/diffraction/WK_scattering_factors.py
+++ b/py4DSTEM/process/diffraction/WK_scattering_factors.py
@@ -174,14 +174,9 @@ def compute_WK_factor(
         B1 = B / (4.0 * np.pi) ** 2
 
         for jj in range(4):
-            Fphon += (
-                A1[jj]
-                * A1[jj]
-                * (DWF * RI1(B1[jj], B1[jj], G) - RI2(B1[jj], B1[jj], G, UL))
-            )
             for ii in range(jj + 1):
                 Fphon += (
-                    2.0
+                    (2.0 if jj != ii else 1.0)
                     * A1[jj]
                     * A1[ii]
                     * (DWF * RI1(B1[ii], B1[jj], G) - RI2(B1[ii], B1[jj], G, UL))