diff --git a/env_vars b/env_vars
index 8d4cae3..018a564 100644
--- a/env_vars
+++ b/env_vars
@@ -13,6 +13,7 @@ readonly VM_LIN_X86="vm-linux"
 readonly VM_LIN_ARM="vm-linux-arm"
 readonly VM_MAC_X86="vm-macos"
 readonly VM_MAC_ARM="vm-macos-arm"
+readonly VM_MAC="vm-macos-unified"
 readonly VM_WIN_X86="vm-win"
 readonly VM_WIN_ARM="vm-win-arm"
 
diff --git a/helpers_bundles.sh b/helpers_bundles.sh
index 1021b81..a5bc267 100644
--- a/helpers_bundles.sh
+++ b/helpers_bundles.sh
@@ -139,3 +139,77 @@ copy_resources() {
     cp -R "${TMP_PATH}/ExampleEtoys" "${target}/"
   fi
 }
+
+# Make a fat binary from a pair of VMs in
+# build.macos64{x64,ARMv8}/virtend.cog.spur/Virtend*.app
+# To choose the oldest nib the oldest deployment target (x86_64) should be last
+create_unified_vm_macOS() {
+  local MISMATCHINGNIBS=
+  local MISMATCHINGPLISTS=
+
+  readonly O="$1"
+  readonly A="$2"
+  readonly B="$3"
+
+  if [ ! -d "$A" ]; then
+    echo "$A does not exist; aborting"
+    exit 44
+  fi
+
+  if [ ! -d "$B" ]; then
+    echo "$B does not exist; aborting"
+    exit 45
+  fi
+
+  echo "merging $A \& $B into $O..."
+  mkdir -p $O
+
+  for f in `cd $A >/dev/null; find . | sed 's|^\.\/||'`; do
+    if [ -d "$A/$f" ]; then
+      mkdir -p $O/$f
+    # elif [ -L "$A/$f" ]; then
+    #   echo ln -s `readlink "$A/$f"` "$O/$f"
+    elif [ ! -f "$A/$f" ]; then
+      echo  "$A/$f does not exist; how come?"
+    elif [ ! -f "$B/$f" ]; then
+      echo  "$B/$f does not exist; how come?"
+    else
+      case `file -b "$A/$f"` in
+        Mach-O*)
+          lipo -create -output "$O/$f" "$A/$f" "$B/$f";;
+        *)
+          if cmp -s "$A/$f" "$B/$f"; then
+            cp "$A/$f" "$O/$f"
+          else
+            echo "EXCLUDING $f because it differs"
+            case "$f" in
+              *.plist)
+                MISMATCHINGPLISTS="$MISMATCHINGPLISTS $f"
+                ;;
+              *.nib)
+                MISMATCHINGNIBS="$MISMATCHINGNIBS   $f"
+                echo "using $B version"
+                cp "$B/$f" "$O/$f"
+                ;;
+            esac
+          fi
+      esac
+    fi
+  done
+
+  if [ -n "$MISMATCHINGPLISTS" ]; then
+    echo "Builds $A \& $B are NOT in perfect sync. Rebuild one or other to resolve"
+    for f in $MISMATCHINGPLISTS; do
+      echo "$f"
+      diff $A/$f $B/$f
+    done
+    exit 46
+  fi
+
+  if [ -n "$MISMATCHINGNIBS" ]; then
+    echo "Builds $A \& $B are NOT in perfect sync. ui nibs differ. Took $B\'s"
+    for f in $MISMATCHINGNIBS; do
+      echo $f
+    done
+  fi
+}
\ No newline at end of file
diff --git a/prepare_bundle_macos.sh b/prepare_bundle_macos.sh
new file mode 100644
index 0000000..f4d30ce
--- /dev/null
+++ b/prepare_bundle_macos.sh
@@ -0,0 +1,57 @@
+#!/usr/bin/env bash
+################################################################################
+#  PROJECT: Squeak Bundle Generation
+#  FILE:    prepare_bundle_macos_arm.sh
+#  CONTENT: Generate bundle for macOS (unified, arm64 and x64).
+#
+#  AUTHORS: Fabio Niephaus, Hasso Plattner Institute, Potsdam, Germany
+#           Marcel Taeumel, Hasso Plattner Institute, Potsdam, Germany
+################################################################################
+
+begin_group "Creating macOS bundle for ${SMALLTALK_VERSION}..."
+BUNDLE_NAME_MAC="${IMAGE_NAME}-${VERSION_VM_MACOS}"
+export_variable "BUNDLE_NAME_MAC" "${BUNDLE_NAME_MAC}"
+BUNDLE_ID_MAC="org.squeak.$(echo ${SQUEAK_VERSION} | tr '[:upper:]' '[:lower:]')-${IMAGE_BITS}bit"
+APP_NAME="${IMAGE_NAME}.app"
+APP_PATH="${BUILD_PATH}/${APP_NAME}"
+CONTENTS_PATH="${APP_PATH}/Contents"
+RESOURCES_PATH="${CONTENTS_PATH}/Resources"
+VM_MAC_TARGET="${CONTENTS_PATH}/MacOS"
+
+echo "...copying macOS VM (unified)..."
+if is_dir "${TMP_PATH}/${VM_MAC}/Squeak.app"; then
+  cp -R "${TMP_PATH}/${VM_MAC}/Squeak.app" "${APP_PATH}"
+else
+  echo "Unable to locate macOS VM." && exit 1
+fi
+
+copy_resources "${RESOURCES_PATH}"
+
+echo "...merging template..."
+cp "${MAC_TEMPLATE_PATH}/Squeak.app/Contents/Info.plist" "${CONTENTS_PATH}/"
+cp "${ICONS_PATH}/${SMALLTALK_NAME}"*.icns "${RESOURCES_PATH}/"
+ENGLISH_PATH="${MAC_TEMPLATE_PATH}/Squeak.app/Contents/Resources/English.lproj"
+cp "${ENGLISH_PATH}/Credits.rtf" "${RESOURCES_PATH}/English.lproj/"
+
+echo "...setting permissions..."
+chmod +x "${VM_MAC_TARGET}/Squeak"
+
+echo "...patching Info.plist..."
+# Info.plist
+sed -i".bak" "s/%SmalltalkName%/${SMALLTALK_NAME}/g" "${CONTENTS_PATH}/Info.plist"
+sed -i".bak" "s/%CFBundleGetInfoString%/${BUNDLE_NAME_MAC}/g" "${CONTENTS_PATH}/Info.plist"
+sed -i".bak" "s/%CFBundleIdentifier%/${BUNDLE_ID_MAC}/g" "${CONTENTS_PATH}/Info.plist"
+sed -i".bak" "s/%CFBundleName%/${SMALLTALK_NAME}/g" "${CONTENTS_PATH}/Info.plist"
+sed -i".bak" "s/%CFBundleShortVersionString%/${SQUEAK_VERSION_NUMBER}/g" "${CONTENTS_PATH}/Info.plist"
+sed -i".bak" "s/%CFBundleVersion%/${IMAGE_BITS} bit/g" "${CONTENTS_PATH}/Info.plist"
+sed -i".bak" "s/%SqueakImageName%/${IMAGE_NAME}.image/g" "${CONTENTS_PATH}/Info.plist"
+rm -f "${CONTENTS_PATH}/Info.plist.bak"
+
+if should_codesign; then
+  do_codesign "${APP_PATH}" # *.app
+fi
+
+compress_into_product_macOS "${APP_PATH}" "${BUNDLE_NAME_MAC}"
+reset_build_dir
+
+end_group
diff --git a/prepare_bundles.sh b/prepare_bundles.sh
index 5971213..38040b1 100755
--- a/prepare_bundles.sh
+++ b/prepare_bundles.sh
@@ -67,6 +67,7 @@ if should_use_rc_vm; then
 else
   download_and_extract_all_vms
 fi
+create_unified_vm_macOS "${TMP_PATH}/${VM_MAC}" "${TMP_PATH}/${VM_MAC_ARM}" "${TMP_PATH}/${VM_MAC_X86}"
 
 if should_codesign; then
   source "helpers_codesign.sh"
@@ -75,12 +76,12 @@ fi
 
 prepare_image_bundle # Just .image and .changes in an archive
 if is_64bit; then
-# source "prepare_bundle_aio.sh"
-# source "prepare_bundle_macos.sh" # Unified binary x86+ARM
+  source "prepare_bundle_macos.sh" # Unified binary arm64+x64
   source "prepare_bundle_macos_x86.sh"
   source "prepare_bundle_macos_arm.sh"
 fi
 
+source "prepare_bundle_aio.sh"
 source "prepare_bundle_linux_x86.sh"
 source "prepare_bundle_linux_arm.sh"
 source "prepare_bundle_windows_x86.sh"