diff --git a/pkgs/development/tools/continuous-integration/buildbot/master.nix b/pkgs/development/tools/continuous-integration/buildbot/master.nix
index 68b5d8ed373a..714e1d42f915 100644
--- a/pkgs/development/tools/continuous-integration/buildbot/master.nix
+++ b/pkgs/development/tools/continuous-integration/buildbot/master.nix
@@ -22,7 +22,7 @@
 , pypugjs
 , boto3
 , moto
-, mock
+, markdown
 , lz4
 , setuptoolsTrial
 , buildbot-worker
@@ -65,14 +65,14 @@ let
 
   package = buildPythonApplication rec {
     pname = "buildbot";
-    version = "3.8.0";
+    version = "3.9.0";
     format = "setuptools";
 
     disabled = pythonOlder "3.7";
 
     src = fetchPypi {
       inherit pname version;
-      hash = "sha256-Z4BmC6Ed+7y4rJologiLXhkIvucXz65KEBxX3LFqExY=";
+      hash = "sha256-NP2nk9uVIyZOyil4KX+NyG1Z9YTSxDVA2ceMuO6JNH4=";
     };
 
     propagatedBuildInputs = [
@@ -98,7 +98,7 @@ let
       pypugjs
       boto3
       moto
-      mock
+      markdown
       lz4
       setuptoolsTrial
       buildbot-worker
diff --git a/pkgs/development/tools/continuous-integration/buildbot/pkg.nix b/pkgs/development/tools/continuous-integration/buildbot/pkg.nix
index a72ae5120438..55b8bdccb048 100644
--- a/pkgs/development/tools/continuous-integration/buildbot/pkg.nix
+++ b/pkgs/development/tools/continuous-integration/buildbot/pkg.nix
@@ -6,7 +6,7 @@ buildPythonPackage rec {
 
   src = fetchPypi {
     inherit pname version;
-    hash = "sha256-duv8oKgVGfeOzjKiI8Ltmto0dcGSI1xtSy8YbqtIFTk=";
+    hash = "sha256-y0BRDB2L7aWCJJ25oL2HZ80ijZ2Ebm5d5WY0UnFgbo8=";
   };
 
   postPatch = ''
diff --git a/pkgs/development/tools/continuous-integration/buildbot/plugins.nix b/pkgs/development/tools/continuous-integration/buildbot/plugins.nix
index 15e9ebbe20bb..495fa6dd50b1 100644
--- a/pkgs/development/tools/continuous-integration/buildbot/plugins.nix
+++ b/pkgs/development/tools/continuous-integration/buildbot/plugins.nix
@@ -8,7 +8,7 @@
 
     src = fetchPypi {
       inherit pname version;
-      hash = "sha256-6hLJADdd84LTpxVB8C+i8rea9/65QfcCPuZC/7+55Co=";
+      hash = "sha256-jdeVojfC421cxjXYFjlmIeEBuraqMnukAO1QZVPE2Oc=";
     };
 
     # Remove unnecessary circular dependency on buildbot
@@ -35,7 +35,7 @@
 
     src = fetchPypi {
       inherit pname version;
-      hash = "sha256-JA+3WnZAN4224LbrluHJcnTmQ8VnuAmoEqqLtw0H10M=";
+      hash = "sha256-JFzdK/DkPxwoPRaEbULNw3O3NGEIlMGrDKTVICAxdkI=";
     };
 
     buildInputs = [ buildbot-pkg ];
@@ -57,7 +57,7 @@
 
     src = fetchPypi {
       inherit pname version;
-      hash = "sha256-NwLb9aQQwOxo9AqvsYbl/g8mNUeufdPrCwFMJNzdfQM=";
+      hash = "sha256-+PrGubM/EOw1QTUyYPy51PzuOVZ8rjCcZpeIUybm3q8=";
     };
 
     buildInputs = [ buildbot-pkg ];
@@ -79,7 +79,7 @@
 
     src = fetchPypi {
       inherit pname version;
-      hash = "sha256-hIBH8+RvZ53Txxl2FyrCs+ZFzRAAbK2th5Im2gZCs3c=";
+      hash = "sha256-k93slBfR0rTJ0hmXG3nAMU/ar9hjX9+BPXD87DajaTU=";
     };
 
     buildInputs = [ buildbot-pkg ];
@@ -101,7 +101,7 @@
 
     src = fetchPypi {
       inherit pname version;
-      hash = "sha256-iK9MwE5Nzc0tHMui0LquCqTFIPbRTEYeHam+5hiOQJE=";
+      hash = "sha256-oKIHLllzeyAm2BsVbZE68h53V1WQjWlYDLpd73FVOe0=";
     };
 
     buildInputs = [ buildbot-pkg ];
@@ -123,7 +123,7 @@
 
     src = fetchPypi {
       inherit pname version;
-      hash = "sha256-HtVleYQE+pfwso7oBNucRjHEkwjgQSZJ6Ts1x7ncLsA=";
+      hash = "sha256-XPStbcijZJTmaR2mjyWSY1UCZmHpS7xF/vg/CsMR6+4=";
     };
 
     buildInputs = [ buildbot-pkg ];
diff --git a/pkgs/development/tools/continuous-integration/buildbot/worker.nix b/pkgs/development/tools/continuous-integration/buildbot/worker.nix
index baf34ad683e0..29ee6e2467df 100644
--- a/pkgs/development/tools/continuous-integration/buildbot/worker.nix
+++ b/pkgs/development/tools/continuous-integration/buildbot/worker.nix
@@ -13,7 +13,6 @@
 , twisted
 
 # tests
-, mock
 , parameterized
 , psutil
 , setuptoolsTrial
@@ -28,7 +27,7 @@ buildPythonPackage (rec {
 
   src = fetchPypi {
     inherit pname version;
-    hash = "sha256-et0R0pNxtL5QCgHRT1/q5t+hb6cLl6NU3AowzT/WC90=";
+    hash = "sha256-L7TKo+4RDqHVVB/0ujR3jDxD+emvcEHdHTLyHe9jdk4=";
   };
 
   postPatch = ''
@@ -48,7 +47,6 @@ buildPythonPackage (rec {
   ];
 
   nativeCheckInputs = [
-    mock
     parameterized
     psutil
   ];