diff --git a/build.sh b/build.sh
index fbf24ca..50d6d1e 100755
--- a/build.sh
+++ b/build.sh
@@ -3,7 +3,7 @@
 # Distributed under the MIT License (MIT) (See accompanying file LICENSE.txt
 # or copy at http://opensource.org/licenses/MIT)
 
-mkdir build
+mkdir -p build
 cd build
 # generate solution for GCC
 cmake ..