diff --git a/scripts/build-image.sh b/scripts/build-image.sh
index 1b92b5c..f08d8b2 100755
--- a/scripts/build-image.sh
+++ b/scripts/build-image.sh
@@ -34,6 +34,19 @@ if [ -z "${GAMECI_VERSION}" ]; then
     GAMECI_VERSION=3
 fi
 
+# Ensure IMAGE_OS is set, default to ubuntu if not
+if [ -z "${IMAGE_OS}" ]; then
+    IMAGE_OS="ubuntu"
+
+    # windows-il2cpp requires windows OS
+    if [ "${UNITY_PLATFORM}" = "windows-il2cpp" ]; then
+        IMAGE_OS="windows"
+    fi
+
+    # TODO: MacOS probably requires a mac image. 
+    # Might be worth just putting this in the strategy at this point
+fi
+
 # Ensure PLATFORM is set, default to the current system if not
 if [ -z "${PLATFORM}" ]; then
     PLATFORM=$(uname -m)
@@ -47,8 +60,9 @@ if [ -z "${PLATFORM}" ]; then
     esac
 fi
 
-BASE_IMAGE=unityci/editor:ubuntu-${UNITY_VERSION}-${UNITY_PLATFORM}-${GAMECI_VERSION}
-TAG=ubuntu-${UNITY_VERSION}-${UNITY_PLATFORM}-runner
+
+BASE_IMAGE=unityci/editor:${IMAGE_OS}-${UNITY_VERSION}-${UNITY_PLATFORM}-${GAMECI_VERSION}
+TAG=${IMAGE_OS}-${UNITY_VERSION}-${UNITY_PLATFORM}-runner
 FULL_IMAGE=${IMAGE}:${TAG}
 
 echo "Building Docker image ${FULL_IMAGE}"