diff --git a/build/common.sh b/build/common.sh
index 4bd6331b7b6..f97f38a1b90 100755
--- a/build/common.sh
+++ b/build/common.sh
@@ -173,7 +173,7 @@ function kube::build::docker_available_on_osx() {
     
     kube::log::status "No docker host is set. Checking options for setting one..."
     if [[ -z "$(which docker-machine)" && -z "$(which boot2docker)" ]]; then
-      kube::log::status "It looks like you're running Mac OS X, and neither Docker for Mac, docker-machine or boot2docker are nowhere to be found."
+      kube::log::status "It looks like you're running Mac OS X, yet none of Docker for Mac, docker-machine or boot2docker are on the path."
       kube::log::status "See: https://docs.docker.com/machine/ for installation instructions."
       return 1
     elif [[ -n "$(which docker-machine)" ]]; then
@@ -242,11 +242,15 @@ function kube::build::is_osx() {
   [[ "$(uname)" == "Darwin" ]]
 }
 
+function kube::build::is_gnu_sed() {
+  [[ $(sed --version 2>&1) == *GNU* ]]
+}
+
 function kube::build::update_dockerfile() {
-  if kube::build::is_osx; then
-    sed_opts=(-i '')
-  else
+  if kube::build::is_gnu_sed; then
     sed_opts=(-i)
+  else
+    sed_opts=(-i '')
   fi
   sed "${sed_opts[@]}" "s/KUBE_BUILD_IMAGE_CROSS_TAG/${KUBE_BUILD_IMAGE_CROSS_TAG}/" "${LOCAL_OUTPUT_BUILD_CONTEXT}/Dockerfile"
 }