diff --git a/HPC_setup/requirements_HDFML_additionals.txt b/HPC_setup/requirements_HDFML_additionals.txt
index 12e09ccdd620c0c81c78ae6d4781d4feb5b94baf..26e335d56d014abfb20ea68010c029660f492443 100644
--- a/HPC_setup/requirements_HDFML_additionals.txt
+++ b/HPC_setup/requirements_HDFML_additionals.txt
@@ -2,6 +2,7 @@ absl-py==0.11.0
 appdirs==1.4.4
 astor==0.8.1
 attrs==20.3.0
+bottleneck==1.3.2
 cached-property==1.5.2
 certifi==2020.12.5
 cftime==1.4.1
diff --git a/HPC_setup/requirements_JUWELS_additionals.txt b/HPC_setup/requirements_JUWELS_additionals.txt
index 12e09ccdd620c0c81c78ae6d4781d4feb5b94baf..26e335d56d014abfb20ea68010c029660f492443 100644
--- a/HPC_setup/requirements_JUWELS_additionals.txt
+++ b/HPC_setup/requirements_JUWELS_additionals.txt
@@ -2,6 +2,7 @@ absl-py==0.11.0
 appdirs==1.4.4
 astor==0.8.1
 attrs==20.3.0
+bottleneck==1.3.2
 cached-property==1.5.2
 certifi==2020.12.5
 cftime==1.4.1
diff --git a/mlair/helpers/statistics.py b/mlair/helpers/statistics.py
index 3631597aedb90b3411163a42490e9c023bad706a..57d7802e58c69f39e17aaa244871b68dfaba00b7 100644
--- a/mlair/helpers/statistics.py
+++ b/mlair/helpers/statistics.py
@@ -616,9 +616,11 @@ class KolmogorovZurbenkoFilterMovingWindow(KolmogorovZurbenkoBaseClass):
              wl(int): a window length
              itr(int): a number of iteration
         """
+        import warnings
+        warnings.filterwarnings("ignore")
         df_itr = df.__deepcopy__()
         try:
-            kwargs = {"min_periods": 1,
+            kwargs = {"min_periods": int(0.7 * wl),
                       "center": True,
                       self.filter_dim: wl}
             iter_vars = df_itr.coords["variables"].values
diff --git a/requirements.txt b/requirements.txt
index b0a6e7f59896fd0edf08977ee553c803f6c2e960..51d6e0233c514f15b4724309874ff746234c3b75 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,7 @@ absl-py==0.11.0
 appdirs==1.4.4
 astor==0.8.1
 attrs==20.3.0
+bottleneck==1.3.2
 cached-property==1.5.2
 certifi==2020.12.5
 cftime==1.4.1
diff --git a/requirements_gpu.txt b/requirements_gpu.txt
index 35fe0d5ee2a03f01737bc185d2a5bbaf26383806..11a5c8aeedf513b0f0b2373a4ef992d8d2ec28c7 100644
--- a/requirements_gpu.txt
+++ b/requirements_gpu.txt
@@ -2,6 +2,7 @@ absl-py==0.11.0
 appdirs==1.4.4
 astor==0.8.1
 attrs==20.3.0
+bottleneck==1.3.2
 cached-property==1.5.2
 certifi==2020.12.5
 cftime==1.4.1