diff --git a/pkgs/tools/networking/curl/builder.sh b/pkgs/tools/networking/curl/builder.sh
new file mode 100644
index 000000000000..dd693683cb0d
--- /dev/null
+++ b/pkgs/tools/networking/curl/builder.sh
@@ -0,0 +1,9 @@
+source $stdenv/setup
+
+if test "$sslSupport"; then
+  configureFlags="--with-ssl=$openssl"
+else
+  configureFlags="--without-ssl"
+fi
+
+genericBuild
diff --git a/pkgs/tools/networking/curl/default.nix b/pkgs/tools/networking/curl/default.nix
index abce6fb3a37a..0d3f4a1eded3 100644
--- a/pkgs/tools/networking/curl/default.nix
+++ b/pkgs/tools/networking/curl/default.nix
@@ -4,11 +4,12 @@ assert sslSupport -> openssl != null;
 
 stdenv.mkDerivation {
   name = "curl-7.15.1";
+  builder = ./builder.sh;
   src = fetchurl {
     url = http://nix.cs.uu.nl/dist/tarballs/curl-7.15.1.tar.bz2;
     md5 = "d330d48580bfade58c82d4f295f171f0";
   };
   buildInputs = [zlib (if sslSupport then openssl else null)];
   patches = [./configure-cxxcpp.patch];
-  configureFlags = (if sslSupport then "--with-ssl" else "--without-ssl");
+  inherit sslSupport openssl;
 }