diff --git a/build.sh b/build.sh
index 6bc3032219..a7ff60d4ee 100755
--- a/build.sh
+++ b/build.sh
@@ -1,20 +1,37 @@
 #!/bin/bash
-
-if [[ ! -e ~/.config/.mono/certs ]];
+if test "$OS" = "Windows_NT"
 then
-    mozroots --import --sync --quiet
-fi
+  # use .Net
+  .paket/paket.bootstrapper.exe
+  exit_code=$?
+  if [ $exit_code -ne 0 ]; then
+    exit $exit_code
+  fi
 
-mono .paket/paket.bootstrapper.exe
-exit_code=$?
-if [ $exit_code -ne 0 ]; then
-	exit $exit_code
-fi
+  .paket/paket.exe restore
+  exit_code=$?
+  if [ $exit_code -ne 0 ]; then
+    exit $exit_code
+  fi
 
-mono .paket/paket.exe restore
-exit_code=$?
-if [ $exit_code -ne 0 ]; then
-	exit $exit_code
-fi
+  packages/FAKE/tools/FAKE.exe build.fsx $@
+else
+  # use mono
+  if [[ ! -e ~/.config/.mono/certs ]]; then
+    mozroots --import --sync --quiet
+  fi
+  
+  mono .paket/paket.bootstrapper.exe
+  exit_code=$?
+  if [ $exit_code -ne 0 ]; then
+    exit $exit_code
+  fi
 
-mono --runtime=v4.0 packages/FAKE/tools/FAKE.exe build.fsx -d:MONO "$@"
\ No newline at end of file
+  mono .paket/paket.exe restore
+  exit_code=$?
+  if [ $exit_code -ne 0 ]; then
+    exit $exit_code
+  fi
+  
+  mono packages/FAKE/tools/FAKE.exe $@ --fsiargs -d:MONO build.fsx
+fi
\ No newline at end of file