diff --git a/pkgs/servers/dict/dictd-wordnet.nix b/pkgs/servers/dict/dictd-wordnet.nix
index 663bd54897bf..d9f3c7a99c8c 100644
--- a/pkgs/servers/dict/dictd-wordnet.nix
+++ b/pkgs/servers/dict/dictd-wordnet.nix
@@ -1,10 +1,10 @@
-{lib, stdenv, python3, wordnet, writeScript}:
+{lib, stdenv, python3, wordnet, writeScript, libfaketime}:
 
 stdenv.mkDerivation rec {
   version = "542";
   pname = "dict-db-wordnet";
 
-  buildInputs = [python3 wordnet];
+  buildInputs = [python3 wordnet libfaketime];
   convert = ./wordnet_structures.py;
 
   builder = writeScript "builder.sh" ''
@@ -16,7 +16,8 @@ stdenv.mkDerivation rec {
       DATA="$DATA `echo $i | sed -e s,data,index,` $i";
     done
 
-    python ${convert} $DATA
+    source_date=$(date --utc --date=@$SOURCE_DATE_EPOCH "+%F %T")
+    faketime -f "$source_date" python ${convert} $DATA
     echo en_US.UTF-8 > locale
   '';