diff --git a/build-osx.sh b/build-osx.sh
index 115da8d1..87bb5ada 100755
--- a/build-osx.sh
+++ b/build-osx.sh
@@ -1,5 +1,8 @@
 #!/bin/bash
 
+# for sha256sum, used by the tests
+brew install coreutils
+
 BUILD_DIR=build-osx
 EMBREE_ZIP="https://github.com/embree/embree/releases/download/v3.13.0/embree-3.13.0.x86_64.macosx.zip"