diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 3bc9c07e..5cc190bb 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -78,6 +78,7 @@ jobs:
           NGINX_VERSION: ${{ matrix.NGINX_VERSION }}
           BUILD_DYNAMIC_MODULE: ${{ matrix.BUILD_DYNAMIC_MODULE }}
           BUILD_WITH_OPENSSL_SRC: ${{ matrix.BUILD_WITH_OPENSSL_SRC }}
+          NUM_THREADS: 1
         run: |
           echo "NGINX_SRC_MAJOR=$(echo $NGINX_VERSION | cut -d '.' -f 1)" > nginx_version
           echo "NGINX_SRC_MINOR=$(echo $NGINX_VERSION | cut -d '.' -f 2)" >> nginx_version