diff --git a/.github/workflows/ccpp.yml b/.github/workflows/ccpp.yml
index 0051a468..b8812d02 100644
--- a/.github/workflows/ccpp.yml
+++ b/.github/workflows/ccpp.yml
@@ -28,7 +28,7 @@ jobs:
       run: cd 3rdpart/libsrtp && ./configure --enable-openssl && make -j4 && sudo make install
 
     - name: 编译
-      run: mkdir -p linux_build && cd linux_build && cmake .. -DENABLE_WEBRTC:BOOL=TRUE && make -j ${nproc}
+      run: mkdir -p linux_build && cd linux_build && cmake .. -DENABLE_WEBRTC:BOOL=TRUE && make -j $(nproc)
 
     - name: 运行MediaServer
       run: pwd && cd release/linux/Debug && sudo ./MediaServer -d &
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index d14001e6..103e11d5 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -31,7 +31,7 @@ jobs:
 #      run: cd 3rdpart/libsrtp && ./configure --enable-openssl && make -j4 && sudo make install
 
     - name: 编译
-      run: mkdir -p build && cd build && cmake .. &&  make -j ${nproc}
+      run: mkdir -p build && cd build && cmake .. &&  make -j $(nproc)
 
     - name: 运行MediaServer
       run: pwd && cd release/linux/Debug && sudo ./MediaServer -d &
diff --git a/dockerfile b/dockerfile
index 2be4d056..84b00d3d 100644
--- a/dockerfile
+++ b/dockerfile
@@ -33,7 +33,7 @@ RUN apt-get update && \
          apt-get autoremove -y && \
          apt-get clean -y && \
          wget https://github.com/cisco/libsrtp/archive/v2.2.0.tar.gz -O libsrtp-2.2.0.tar.gz && tar xfv libsrtp-2.2.0.tar.gz && \
-         cd libsrtp-2.2.0 && ./configure --enable-openssl && make -j ${nproc} && make install && \
+         cd libsrtp-2.2.0 && ./configure --enable-openssl && make -j $(nproc) && make install && \
     rm -rf /var/lib/apt/lists/*
 
 RUN mkdir -p /opt/media
@@ -44,7 +44,7 @@ RUN mkdir -p build release/linux/${MODEL}/
 
 WORKDIR /opt/media/ZLMediaKit/build
 RUN cmake -DCMAKE_BUILD_TYPE=${MODEL} -DENABLE_WEBRTC=true -DENABLE_TESTS=false -DENABLE_API=false .. && \
-    make -j ${nproc}
+    make -j $(nproc)
 
 FROM ubuntu:18.04
 ARG MODEL