diff --git a/ngmix/prepsfmom.py b/ngmix/prepsfmom.py
index 4604e1f7..c015e9bc 100644
--- a/ngmix/prepsfmom.py
+++ b/ngmix/prepsfmom.py
@@ -276,6 +276,23 @@ def _measure_moments_fft(
         cen_phase = _compute_cen_phase_shift(drow, dcol, dim, msk=msk)
         kim *= cen_phase
 
+    # we only sum where the kernel is nonzero
+    fkf = kernels["fkf"]
+    fkr = kernels["fkr"]
+    fkp = kernels["fkp"]
+    fkc = kernels["fkc"]
+
+    mom_norm = kernels["fk00"]
+    return _numba_bits(
+        kim, fkf, fkr, fkp, fkc, eff_pad_factor, kpsf_im, mom_norm, tot_var, dim,
+    )
+
+
+@njit
+def _numba_bits(
+    kim, fkf, fkr, fkp, fkc, eff_pad_factor, kpsf_im, mom_norm, tot_var, dim,
+):
+
     # build the flux, radial, plus and cross kernels / moments
     # the inverse FFT in our convention has a factor of 1/n per dimension
     # the sums below are inverse FFTs but only computing the values at the
@@ -285,13 +302,6 @@ def _measure_moments_fft(
     df2 = df * df
     df4 = df2 * df2
 
-    # we only sum where the kernel is nonzero
-    fkf = kernels["fkf"]
-    fkr = kernels["fkr"]
-    fkp = kernels["fkp"]
-    fkc = kernels["fkc"]
-
-    mom_norm = kernels["fk00"]
     mf = np.sum((kim * fkf).real) * df2
     mr = np.sum((kim * fkr).real) * df2
     mp = np.sum((kim * fkp).real) * df2
@@ -397,10 +407,16 @@ def _compute_cen_phase_shift(cen_row, cen_col, dim, msk=None):
     fx = f.reshape(1, -1)
     fy = f.reshape(-1, 1)
     kcen = fy*cen_row + fx*cen_col
+
     if msk is not None:
-        return np.cos(kcen[msk]) + 1j*np.sin(kcen[msk])
-    else:
-        return np.cos(kcen) + 1j*np.sin(kcen)
+        kcen = kcen[msk]
+
+    return _comp_phase(kcen)
+
+
+@njit
+def _comp_phase(kcen):
+    return np.cos(kcen) + 1j*np.sin(kcen)
 
 
 def _zero_pad_and_compute_fft_impl(im, cen_row, cen_col, target_dim, ap_rad):
diff --git a/ngmix/tests/test_prepsfmom.py b/ngmix/tests/test_prepsfmom.py
index 7b4cdd77..6488b9a0 100644
--- a/ngmix/tests/test_prepsfmom.py
+++ b/ngmix/tests/test_prepsfmom.py
@@ -211,7 +211,7 @@ def test_prepsfmom_speed_and_cache():
     assert _zero_pad_and_compute_fft_cached_impl.cache_info().misses == 4
 
     # now we test with full caching
-    nfit = 1000
+    nfit = 2000
     dt = time.time()
     for _ in range(nfit):
         with obs.writeable():