diff --git a/pkgs/development/libraries/opencascade/default.nix b/pkgs/development/libraries/opencascade/default.nix
index 2f178edccd5..56c97f7686e 100644
--- a/pkgs/development/libraries/opencascade/default.nix
+++ b/pkgs/development/libraries/opencascade/default.nix
@@ -9,7 +9,10 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ mesa qt4 tcl tk];
 
-  preConfigure = "cd ros";
+  preConfigure = ''
+    export LDFLAGS=-L$out/lib
+    cd ros
+  '';
 
   postInstall = ''
     mv $out/inc $out/include
diff --git a/pkgs/os-specific/linux/kernel/builder.sh b/pkgs/os-specific/linux/kernel/builder.sh
index 75283e835de..48e173e1baa 100644
--- a/pkgs/os-specific/linux/kernel/builder.sh
+++ b/pkgs/os-specific/linux/kernel/builder.sh
@@ -40,7 +40,9 @@ configurePhase() {
 postBuild() {
     # After the builder did a 'make all' (kernel + modules)
     # we force building the target asked: bzImage/zImage/uImage/...
-    make $makeFlags $kernelTarget
+    if [ "$kernelTarget" != "vmlinuz" ]; then
+        make $makeFlags $kernelTarget
+    fi
 }
 
 installPhase() {