diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 945544a9..d21e3d9c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -4,8 +4,8 @@ on:
   - pull_request
 
 jobs:
-  natives-linux-windows:
-    name: Linux (x86/ARM/PPC) and Windows native library compilation
+  natives-linux:
+    name: Linux (x86_64) native library compilation
     runs-on: ubuntu-18.04
 
     defaults:
@@ -22,12 +22,11 @@ jobs:
       - name: Install build prerequisites
         run: |
           sudo apt update
-          sudo make crosstools
 
-      - name: Build the Linux and Windows native libraries
+      - name: Build the Linux native libraries (x86_64 only)
         run: |
-          make clean-linux clean-windows
-          make linux windows
+          make clean-linux
+          make linux64
 
       # The names of the artifacts containing native libraries correspond
       # exactly to the directories inside `src/main/c/resources/native`. That
@@ -43,82 +42,13 @@ jobs:
         with:
           name: linux
           path: src/main/c/resources/native/linux
-      - name: Upload Windows native libraries
-        uses: actions/upload-artifact@v2
-        with:
-          name: windows
-          path: src/main/c/resources/native/windows
-
-  natives-macos:
-    name: macOS native library compilation
-    runs-on: macos-10.15
-
-    defaults:
-      run:
-        working-directory: src/main/c
-
-    steps:
-      - name: Checkout the code
-        uses: actions/checkout@v2
-      - name: Setup Java
-        uses: actions/setup-java@v1
-        with:
-          java-version: 8
-
-      - name: Build the macOS native libraries
-        run: |
-          make clean-osx
-          make osx
-
-      - name: Upload macOS native libraries
-        uses: actions/upload-artifact@v2
-        with:
-          name: osx
-          path: src/main/c/resources/native/osx/libNRJavaSerial.jnilib
-
-  natives-freebsd:
-    name: FreeBSD native library compilation
-    runs-on: ubuntu-18.04
-    container:
-      image: empterdose/freebsd-cross-build:9.3
-      env:
-        JAVA_HOME: /usr/lib/jvm/default-jvm
-
-    defaults:
-      run:
-        working-directory: src/main/c
-
-    steps:
-      - name: Checkout the code
-        uses: actions/checkout@v2
-      - name: Setup Java
-        # This feels extremely dirty, but the only native header we care about
-        # is `jni_md.h`, and it is exactly identical between Linux and FreeBSD
-        # (at least in OpenJDK 8).
-        run: |
-          apk add openjdk8
-          ln -s $JAVA_HOME/include/linux $JAVA_HOME/include/freebsd
-
-      - name: Build the FreeBSD native libraries
-        run: |
-          make clean-freebsd
-          settarget i386-freebsd9 make freebsd32
-          settarget x86_64-freebsd9 make freebsd64
-
-      - name: Upload FreeBSD native libraries
-        uses: actions/upload-artifact@v2
-        with:
-          name: freebsd
-          path: src/main/c/resources/native/freebsd
 
   java:
     name: Java compilation
     runs-on: ubuntu-18.04
 
     needs:
-      - natives-linux-windows
-      - natives-macos
-      - natives-freebsd
+      - natives-linux
 
     steps:
       - name: Checkout the code