diff --git a/Dockerfile b/Dockerfile
index 39b8bab..5c5d3e6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -127,7 +127,7 @@ RUN <<EOF
         -DgRPC_BUILD_TESTS=OFF \
         -DgRPC_SSL_PROVIDER=package \
         ../..
-    make -j4 install
+    make -j$(($(nproc)-1)) install
 EOF
 
 FROM build_grpc AS build_grpc_arm
@@ -157,7 +157,7 @@ RUN <<EOF
         -DCMAKE_FIND_ROOT_PATH="$SDKTARGETSYSROOT"/usr \
         -DCMAKE_BUILD_TYPE=Release \
         ../..
-    make -j4 install/strip
+    make -j$(($(nproc)-1)) install/strip
     cp -r /opt/grpc/third_party/googletest/googletest/include/gtest \
         "$SDKTARGETSYSROOT"/usr/include
 EOF