diff --git a/README.md b/README.md
index 08ae1bf..f2fbbe0 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ Build and run unit tests and benchmark
 --------------------------------------
 
  * Install Xcode Command Line Tools
+ * Install Eigen with `brew install eigen` (you will need Homebrew)
  * Run the following commands in Terminal
 
 ```bash
diff --git a/test/Makefile b/test/Makefile
index 9867fff..b6fa62e 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -1,7 +1,8 @@
 METAL_CPP_DIR = ../metal-cpp_macOS14.2_iOS17.2
+HOMEBREW_INC = /opt/homebrew/include
 
 CXX = clang++
-CXXFLAGS = -std=c++20 -O2 -I$(METAL_CPP_DIR) -I../include -framework Foundation -framework Metal -framework MetalKit
+CXXFLAGS = -std=c++20 -O2 -I$(METAL_CPP_DIR) -I$(HOMEBREW_INC) -I../include -framework Foundation -framework Metal -framework MetalKit
 
 INC = ../include/metal.h ../include/array.h ../include/mtlcpp.h