diff --git a/circle.yml b/circle.yml
index 8417f8e64..661b64b53 100644
--- a/circle.yml
+++ b/circle.yml
@@ -237,7 +237,7 @@ commands:
           name: Build
           command: |
             ccache --zero-stats --max-size=2G
-            cmake --build build -j $(nproc) << parameters.build_params >>
+            cmake --build build -j $(nproc 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null) << parameters.build_params >>
             ccache --show-stats
   install:
     steps: