diff --git a/pkgs/applications/virtualization/virtualbox/default.nix b/pkgs/applications/virtualization/virtualbox/default.nix
index df0cf3e2aae..8756b043f1f 100644
--- a/pkgs/applications/virtualization/virtualbox/default.nix
+++ b/pkgs/applications/virtualization/virtualbox/default.nix
@@ -17,18 +17,19 @@ let
 
   forEachModule = action: ''
     for mod in \
-      $sourcedir/out/linux.*/release/bin/src/vboxdrv \
-      $sourcedir/out/linux.*/release/bin/src/vboxpci \
-      $sourcedir/out/linux.*/release/bin/src/vboxnetadp \
-      $sourcedir/out/linux.*/release/bin/src/vboxnetflt
+      out/linux.*/release/bin/src/vboxdrv \
+      out/linux.*/release/bin/src/vboxpci \
+      out/linux.*/release/bin/src/vboxnetadp \
+      out/linux.*/release/bin/src/vboxnetflt
     do
       if [ "x$(basename "$mod")" != xvboxdrv -a ! -e "$mod/Module.symvers" ]
       then
-        cp -v $sourcedir/out/linux.*/release/bin/src/vboxdrv/Module.symvers \
-              "$mod/Module.symvers"
+        cp -v out/linux.*/release/bin/src/vboxdrv/Module.symvers \
+          "$mod/Module.symvers"
       fi
       INSTALL_MOD_PATH="$out" INSTALL_MOD_DIR=misc \
-      make -C "$MODULES_BUILD_DIR" "M=$mod" DEPMOD=/do_not_use_depmod ${action}
+      make -C "$MODULES_BUILD_DIR" DEPMOD=/do_not_use_depmod \
+        "M=\$(PWD)/$mod" ${action}
     done
   '';
 
@@ -87,7 +88,6 @@ in stdenv.mkDerivation {
   patches = optional enableHardening ./hardened.patch;
 
   configurePhase = ''
-    sourcedir="$(pwd)"
     cat >> LocalConfig.kmk <<LOCAL_CONFIG
     VBOX_WITH_TESTCASES            :=
     VBOX_WITH_TESTSUITE            :=
@@ -133,9 +133,9 @@ in stdenv.mkDerivation {
     share="${if enableHardening then "$out/share/virtualbox" else "$libexec"}"
 
     # Install VirtualBox files
-    cd out/linux.*/release/bin
-    mkdir -p $libexec
-    cp -av * $libexec
+    mkdir -p "$libexec"
+    find out/linux.*/release/bin -mindepth 1 -maxdepth 1 \
+      -name src -o -exec cp -avt "$libexec" {} +
 
     # Install kernel modules
     ${forEachModule "modules_install"}
@@ -169,9 +169,6 @@ in stdenv.mkDerivation {
       ln -s $libexec/icons/$size/*.png $out/share/icons/hicolor/$size/apps
     done
 
-    # Get rid of src cruft.
-    rm -rf $out/libexec/virtualbox/src
-
     # Get rid of a reference to linux.dev.
     nuke-refs $out/lib/modules/*/misc/*.ko
   '';