diff --git a/pkgs/build-support/release/ant-build.nix b/pkgs/build-support/release/ant-build.nix
index e761205f663..4c8d5fbac75 100644
--- a/pkgs/build-support/release/ant-build.nix
+++ b/pkgs/build-support/release/ant-build.nix
@@ -10,7 +10,7 @@
 , ... } @ args:
 
 let
-  antFlags = "-f ${buildfile} " + stdenv.lib.concatMapStrings ({name, value}: "-D${name}=${value}" ) antProperties ;
+  antFlags = "-f ${buildfile} " + stdenv.lib.concatMapStrings ({name, value}: "-D${name}=${value} " ) antProperties ;
 in
 stdenv.mkDerivation (