diff --git a/bin/aninja b/bin/aninja
index cceb79489..5acb9681c 100755
--- a/bin/aninja
+++ b/bin/aninja
@@ -20,6 +20,19 @@ source $(cd $(dirname $BASH_SOURCE) &> /dev/null && pwd)/../../make/shell_utils.
 require_top
 require_lunch
 
-cd $(gettop)
-prebuilts/build-tools/linux-x86/bin/ninja -f out/combined-${TARGET_PRODUCT}.ninja "$@"
+case $(uname -s) in
+    Darwin)
+        host_arch=darwin-x86
+        ;;
+    Linux)
+        host_arch=linux-x86
+        ;;
+    *)
+        >&2 echo Unknown host $(uname -s)
+        exit 1
+        ;;
+esac
+
+cd $(gettop)
+prebuilts/build-tools/${host_arch}/bin/ninja -f out/combined-${TARGET_PRODUCT}.ninja "$@"