diff --git a/nixos/modules/services/mail/spamassassin.nix b/nixos/modules/services/mail/spamassassin.nix
index 49d1d9315985..4b5736dfd1bc 100644
--- a/nixos/modules/services/mail/spamassassin.nix
+++ b/nixos/modules/services/mail/spamassassin.nix
@@ -79,7 +79,6 @@ in
           loadplugin Mail::SpamAssassin::Plugin::DKIM
           loadplugin Mail::SpamAssassin::Plugin::DNSEval
           loadplugin Mail::SpamAssassin::Plugin::FreeMail
-          loadplugin Mail::SpamAssassin::Plugin::Hashcash
           loadplugin Mail::SpamAssassin::Plugin::HeaderEval
           loadplugin Mail::SpamAssassin::Plugin::HTMLEval
           loadplugin Mail::SpamAssassin::Plugin::HTTPSMismatch
diff --git a/pkgs/servers/mail/spamassassin/default.nix b/pkgs/servers/mail/spamassassin/default.nix
index ef87288df29b..996db226e0d1 100644
--- a/pkgs/servers/mail/spamassassin/default.nix
+++ b/pkgs/servers/mail/spamassassin/default.nix
@@ -1,12 +1,12 @@
-{ lib, fetchurl, perlPackages, makeWrapper, gnupg, re2c, gcc, gnumake }:
+{ lib, fetchurl, perlPackages, makeWrapper, gnupg, re2c, gcc, gnumake, libxcrypt }:
 
 perlPackages.buildPerlPackage rec {
   pname = "SpamAssassin";
-  version = "3.4.6";
+  version = "4.0.0";
 
   src = fetchurl {
     url = "mirror://apache/spamassassin/source/Mail-${pname}-${version}.tar.bz2";
-    sha256 = "044ng2aazqy8g0m17q0a4939ck1ca4x230q2q7q7jndvwkrpaj5w";
+    hash = "sha256-5aoXBQowvHK6qGr9xgSMrepNHsLsxh14dxegWbgxnog=";
   };
 
   # ExtUtil::MakeMaker is bundled with Perl, but the bundled version
@@ -36,7 +36,7 @@ perlPackages.buildPerlPackage rec {
     mv "rules/"* $out/share/spamassassin/
 
     for n in "$out/bin/"*; do
-      wrapProgram "$n" --prefix PERL5LIB : "$PERL5LIB" --prefix PATH : ${lib.makeBinPath [ gnupg re2c gcc gnumake ]}
+      wrapProgram "$n" --prefix PERL5LIB : "$PERL5LIB" --prefix PATH : ${lib.makeBinPath [ gnupg re2c gcc gnumake ]} --prefix C_INCLUDE_PATH : ${lib.makeSearchPathOutput "include" "include" [ libxcrypt ]}
     done
   '';