diff --git a/pkgs/tools/networking/pmacct/default.nix b/pkgs/tools/networking/pmacct/default.nix
index ffecbfcaf425..2bb6f373727d 100644
--- a/pkgs/tools/networking/pmacct/default.nix
+++ b/pkgs/tools/networking/pmacct/default.nix
@@ -19,7 +19,7 @@ assert withSQLite -> sqlite != null;
 assert withPgSQL -> postgresql != null;
 assert withMysql -> libmysqlclient != null;
 
-let inherit (stdenv.lib) optional; in
+let inherit (stdenv.lib) getDev optional optionalString; in
 
 stdenv.mkDerivation rec {
   version = "1.7.5";
@@ -40,6 +40,9 @@ stdenv.mkDerivation rec {
     ++ optional withPgSQL postgresql
     ++ optional withMysql [ libmysqlclient zlib ];
 
+  MYSQL_CONFIG =
+    optionalString withMysql "${getDev libmysqlclient}/bin/mysql_config";
+
   configureFlags = [
     "--with-pcap-includes=${libpcap}/include"
   ] ++ optional withJansson "--enable-jansson"