diff --git a/unseen/eva.py b/unseen/eva.py
index da1a3d8..2840a5c 100644
--- a/unseen/eva.py
+++ b/unseen/eva.py
@@ -1176,7 +1176,7 @@ def gev_return_curve(
         np.isfinite(boot_event_return_periods)
     ]
     event_return_period_lower_ci = np.quantile(boot_event_return_periods, q)
-    event_return_period_upper_ci = np.quantile(boot_event_return_periods, q - 1)
+    event_return_period_upper_ci = np.quantile(boot_event_return_periods, 1 - q)
     event_data = (
         event_return_period,
         event_return_period_lower_ci,
diff --git a/unseen/fileio.py b/unseen/fileio.py
index 30838c0..7db4383 100644
--- a/unseen/fileio.py
+++ b/unseen/fileio.py
@@ -253,6 +253,7 @@ def open_dataset(
     if no_leap_days:
         ds = ds.sel(time=~((ds[time_dim].dt.month == 2) & (ds[time_dim].dt.day == 29)))
     if rolling_sum_window:
+        ds = ds.compute()
         ds = ds.rolling({time_dim: rolling_sum_window}).sum(dim=time_dim)
     if time_freq:
         assert time_agg, "Provide a time_agg"
diff --git a/unseen/process_utils.py b/unseen/process_utils.py
index 9dca37a..553d561 100644
--- a/unseen/process_utils.py
+++ b/unseen/process_utils.py
@@ -60,7 +60,7 @@ def count_months(event_months):
     return counts
 
 
-def plot_event_seasonality(ds, ax=None, core_dim=None, outfile=None):
+def plot_event_seasonality(ds, ax=None, core_dim="time", outfile=None):
     """Plot event seasonality
 
     Parameters
diff --git a/unseen/stability.py b/unseen/stability.py
index 65e4bf4..8cefdf1 100644
--- a/unseen/stability.py
+++ b/unseen/stability.py
@@ -197,6 +197,11 @@ def plot_return_by_lead(
     ax.set_ylabel(units_label)
     if ylim:
         ax.set_ylim(ylim)
+    else:
+        ymin, ymax = ax.get_ylim()
+        if ymin < 0:
+            ymin = 0
+        ax.set_ylim([ymin, ymax])
     ax.legend()
 
 
@@ -269,6 +274,11 @@ def plot_return_by_time(
     ax.set_ylabel(units_label)
     if ylim:
         ax.set_ylim(ylim)
+    else:
+        ymin, ymax = ax.get_ylim()
+        if ymin < 0:
+            ymin = 0
+        ax.set_ylim([ymin, ymax])
     ax.legend()