diff --git a/pkgs/development/perl-modules/template-toolkit-nix-store.patch b/pkgs/development/perl-modules/template-toolkit-nix-store.patch
new file mode 100644
index 00000000000..402f1cb41be
--- /dev/null
+++ b/pkgs/development/perl-modules/template-toolkit-nix-store.patch
@@ -0,0 +1,23 @@
+diff -rc Template-Toolkit-2.20-orig/lib/Template/Provider.pm Template-Toolkit-2.20/lib/Template/Provider.pm
+*** Template-Toolkit-2.20-orig/lib/Template/Provider.pm	2008-08-06 11:32:02.000000000 +0200
+--- Template-Toolkit-2.20/lib/Template/Provider.pm	2008-11-28 16:37:36.000000000 +0100
+***************
+*** 936,942 ****
+  sub _template_modified {
+      my $self = shift;
+      my $template = shift || return;
+!     return (stat( $template ))[9];
+  }
+  
+  #------------------------------------------------------------------------
+--- 936,945 ----
+  sub _template_modified {
+      my $self = shift;
+      my $template = shift || return;
+!     # Nix specific hack: timestamps of 0 (1-1-1970) should not be
+!     # treated as undefined, so return 1 instead.
+!     my $t = (stat( $template ))[9]; 
+!     return (defined $t && $t == 0) ? 1 : $t;
+  }
+  
+  #------------------------------------------------------------------------
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 98e028a6b3f..7966449f85e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5178,6 +5178,10 @@ let
       sha256 = "13wbh06a76k4ag14lhszmpwv4hb8hlj1d9glizhp8izazl3xf1zg";
     };
     propagatedBuildInputs = [perlAppConfig];
+    patches = [
+      # Needed to make TT works properly on templates in the Nix store.
+      ../development/perl-modules/template-toolkit-nix-store.patch
+    ];
   };
 
   perlTermReadKey = buildPerlPackage {