diff --git a/pkgs/by-name/rs/rspamd/package.nix b/pkgs/by-name/rs/rspamd/package.nix
index 84704aa15f79..bca93857db6b 100644
--- a/pkgs/by-name/rs/rspamd/package.nix
+++ b/pkgs/by-name/rs/rspamd/package.nix
@@ -80,6 +80,7 @@ stdenv.mkDerivation rec {
     "-DDBDIR=/var/lib/rspamd"
     "-DLOGDIR=/var/log/rspamd"
     "-DLOCAL_CONFDIR=/etc/rspamd"
+    "-DENABLE_BLAS=${if withBlas then "ON" else "OFF"}"
     "-DENABLE_JEMALLOC=ON"
     "-DSYSTEM_DOCTEST=ON"
     "-DSYSTEM_FMT=ON"