diff --git a/pkgs/tools/security/himitsu-firefox/default.nix b/pkgs/tools/security/himitsu-firefox/default.nix
index b46286301187..9207ca7646f8 100644
--- a/pkgs/tools/security/himitsu-firefox/default.nix
+++ b/pkgs/tools/security/himitsu-firefox/default.nix
@@ -27,6 +27,10 @@ stdenv.mkDerivation rec {
     himitsu
   ];
 
+  preConfigure = ''
+    export HARECACHE=$(mktemp -d)
+  '';
+
   buildFlags = [ "LIBEXECDIR=$(out)/libexec" ];
 
   # Only install the native component; per the docs:
diff --git a/pkgs/tools/security/himitsu/default.nix b/pkgs/tools/security/himitsu/default.nix
index e48de780d72d..ad91081f9ec0 100644
--- a/pkgs/tools/security/himitsu/default.nix
+++ b/pkgs/tools/security/himitsu/default.nix
@@ -22,6 +22,10 @@ stdenv.mkDerivation rec {
     scdoc
   ];
 
+  preConfigure = ''
+    export HARECACHE=$(mktemp -d)
+  '';
+
   installFlags = [ "PREFIX=" "DESTDIR=$(out)" ];
 
   meta = with lib; {