diff --git a/pkgs/development/python-modules/dotnetcore2/default.nix b/pkgs/development/python-modules/dotnetcore2/default.nix
index caafeb54740f..c885466f5af2 100644
--- a/pkgs/development/python-modules/dotnetcore2/default.nix
+++ b/pkgs/development/python-modules/dotnetcore2/default.nix
@@ -7,7 +7,7 @@
 
 buildPythonPackage rec {
   pname = "dotnetcore2";
-  version = "2.1.8.1";
+  version = "2.1.9";
   format = "wheel";
   disabled = isPy27;
 
@@ -15,7 +15,7 @@ buildPythonPackage rec {
     inherit pname version format;
     python = "py3";
     platform = "manylinux1_x86_64";
-    sha256 = "13zrff5j767d3f8drl397sjhl28winsrfa8pa20svf00xfcsy34s";
+    sha256 = "0h1igixk84md68z7gwj1vd6ki4d5drxh0ih5zww8xcr3qh5r0drb";
   };
 
   nativeBuildInputs = [ unzip ];
diff --git a/pkgs/development/python-modules/dotnetcore2/runtime.patch b/pkgs/development/python-modules/dotnetcore2/runtime.patch
index 54322087a780..28cf10e21d15 100644
--- a/pkgs/development/python-modules/dotnetcore2/runtime.patch
+++ b/pkgs/development/python-modules/dotnetcore2/runtime.patch
@@ -1,7 +1,8 @@
-diff a/dotnetcore2/runtime.py b/dotnetcore2/runtime.py
+diff --git a/dotnetcore2/runtime.py b/dotnetcore2/runtime.py
+index 475e2b4..5b578ec 100644
 --- a/dotnetcore2/runtime.py
 +++ b/dotnetcore2/runtime.py
-@@ -39,13 +39,13 @@ def _get_bin_folder() -> str:
+@@ -41,6 +41,7 @@ def _get_bin_folder() -> str:
  
  
  def get_runtime_path():
@@ -9,6 +10,8 @@ diff a/dotnetcore2/runtime.py b/dotnetcore2/runtime.py
      search_string = os.path.join(_get_bin_folder(), 'dotnet*')
      matches = [f for f in glob.glob(search_string, recursive=True)]
      return matches[0]
+@@ -96,8 +97,7 @@ class _FileLock():
+ 
  
  def ensure_dependencies() -> Optional[str]:
 -    if dist is None: