diff --git a/python/lvmdrp/core/spectrum1d.py b/python/lvmdrp/core/spectrum1d.py
index 8131dec1..82fab291 100644
--- a/python/lvmdrp/core/spectrum1d.py
+++ b/python/lvmdrp/core/spectrum1d.py
@@ -3481,8 +3481,8 @@ def obtainGaussFluxPeaks(self, pos, sigma, replace_error=1e10, plot=False):
         yyv = numpy.linspace(pos_t-kernel_width, pos_t+kernel_width, 2*kernel_width+1, endpoint=True)
         # nfibers x kernel_size pixel values
         v = numpy.exp(-0.5 * ((yyv-pos) / sigma) ** 2) / (fact * sigma)
-        yyv = yyv.T.flatten()
-        v = v.T.flatten() / self._error[yyv.astype(numpy.int32)]
+        yyv = yyv.T.ravel()
+        v = v.T.ravel() / self._error[yyv.astype(numpy.int32)]
         B = sparse.csc_matrix((v, (yyv, xx)), shape=(len(self._data), nfibers))
 
         # invert the projection matrix and solve
diff --git a/python/lvmdrp/functions/imageMethod.py b/python/lvmdrp/functions/imageMethod.py
index 59f76962..18b339be 100644
--- a/python/lvmdrp/functions/imageMethod.py
+++ b/python/lvmdrp/functions/imageMethod.py
@@ -4238,8 +4238,8 @@ def create_pixelmask(in_short_dark, in_long_dark, out_pixmask, in_flat_a=None, i
         fig, ax = create_subplots(to_display=display_plots, figsize=(10,5))
         fig.suptitle(os.path.basename(out_pixmask))
         ax.axvspan(flat_low, flat_high, color="0.7", alpha=0.3)
-        ax.hist(flat_a._data.flatten(), bins=1000, color="tab:blue", alpha=0.5, label=f"flat A ({os.path.basename(in_flat_a)})")
-        ax.hist(flat_b._data.flatten(), bins=1000, color="tab:red", alpha=0.5, label=f"flat B ({os.path.basename(in_flat_b)})")
+        ax.hist(flat_a._data.ravel(), bins=1000, color="tab:blue", alpha=0.5, label=f"flat A ({os.path.basename(in_flat_a)})")
+        ax.hist(flat_b._data.ravel(), bins=1000, color="tab:red", alpha=0.5, label=f"flat B ({os.path.basename(in_flat_b)})")
         ax.axvline(ratio_med, lw=1, ls="--", color="0.2")
         ax.set_xscale("log")
         ax.set_yscale("log")
diff --git a/python/lvmdrp/functions/run_twilights.py b/python/lvmdrp/functions/run_twilights.py
index dffb0498..167a7d3e 100644
--- a/python/lvmdrp/functions/run_twilights.py
+++ b/python/lvmdrp/functions/run_twilights.py
@@ -359,7 +359,7 @@ def fit_fiberflat(in_twilight: str, out_flat: str, out_twilight: str,
     axs[2].set_ylabel("Flat-fielded flat (%)")
     axs[2].set_xlim(1, twilight._fibers)
 
-    x = (flat_twilight._data/flat_twilight._data[0]).flatten()
+    x = (flat_twilight._data/flat_twilight._data[0]).ravel()
     axs[3].axvspan(np.nanmean(x) - np.nanstd(x), np.nanmean(x) + np.nanstd(x), lw=0, alpha=0.1, color="0.2")
     axs[3].hist(x, bins=1000, range=(0.95, 1.05), color="tab:orange")
     axs[3].tick_params(labelleft=False)