diff --git a/pkgs/development/interpreters/tcl/8.6.nix b/pkgs/development/interpreters/tcl/8.6.nix
index 1c6217e79d52..2c3a57df6b81 100644
--- a/pkgs/development/interpreters/tcl/8.6.nix
+++ b/pkgs/development/interpreters/tcl/8.6.nix
@@ -4,13 +4,13 @@ callPackage ./generic.nix (
   args
   // rec {
     release = "8.6";
-    version = "${release}.15";
+    version = "${release}.16";
 
     # Note: when updating, the hash in pkgs/development/libraries/tk/8.6.nix must also be updated!
 
     src = fetchurl {
       url = "mirror://sourceforge/tcl/tcl${version}-src.tar.gz";
-      sha256 = "sha256-hh4Vl1Py4vvW7BSEEDcVsL5WvjNXUiuFjTy7X4k//vE=";
+      hash = "sha256-kcuPphdxxjwmLvtVMFm3x61nV6+lhXr2Jl5LC9wqFKU=";
     };
   }
 )
diff --git a/pkgs/development/libraries/tk/8.6.nix b/pkgs/development/libraries/tk/8.6.nix
index bb5f3e97da64..ca655c01ae44 100644
--- a/pkgs/development/libraries/tk/8.6.nix
+++ b/pkgs/development/libraries/tk/8.6.nix
@@ -11,7 +11,7 @@ callPackage ./generic.nix (
 
     src = fetchurl {
       url = "mirror://sourceforge/tcl/tk${tcl.version}-src.tar.gz";
-      sha256 = "sha256-VQlp81N5+VKzAg86t7ndW/0Rwe98m3xqdfXEmsp5P+w=";
+      hash = "sha256-vp+U01ddSzCZ2EvDwQ3omU3y16pAUggXPHCcxASn5f4=";
     };
 
     patches = [