diff --git a/extras/test/unit/test.sh b/extras/test/unit/test.sh
index 369690ad..b2801a10 100755
--- a/extras/test/unit/test.sh
+++ b/extras/test/unit/test.sh
@@ -3,7 +3,8 @@
 set -e
 
 # build the test binary
-mkdir -p build
+rm -rf build
+mkdir build
 cd build
 cmake -G "CodeBlocks - Unix Makefiles" ..
 make -j4