diff --git a/devshell/run b/devshell/run
index eb2e069..b5ef78d 100755
--- a/devshell/run
+++ b/devshell/run
@@ -5,31 +5,11 @@
 
 ### start fuchsia in qemu with a FVM disk
 
-## Usage: fx run [-S <disk_size>] [-- <run-zircon options>... [-- <qemu options>...]]
-## Use `fx run -- -h` to see options available for `run-zircon`.
-## Use `fx run -- -- -h` to see option available for `qemu`.
-
 set -e
 
 source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/lib/image_build_vars.sh || exit $?
 source "${FUCHSIA_DIR}/buildtools/vars.sh"
 
-while getopts ":S:h" FLAG; do
-  case $FLAG in
-    S) QEMU_DISK_SIZE=$OPTARG;;
-    h)
-      fx-command-help
-      exit 1
-      ;;
-    \?)
-      echo unrecognized option
-      fx-command-help
-      exit 1
-      ;;
-  esac
-done
-shift $((OPTIND-1))
-
 qemu_dir="${BUILDTOOLS_QEMU_DIR}/bin"
 
 # Construction of a qcow image prevents qemu from writing back to the
@@ -43,7 +23,7 @@
 trap 'rm "${qimg}" && rmdir "${qcowdir}"' EXIT
 
 "${qemu_dir}/qemu-img" create -f qcow2 -b "${FUCHSIA_BUILD_DIR}/${IMAGE_FVM_RAW}" \
-  "${qimg}" ${QEMU_DISK_SIZE}
+  "${qimg}"
 
 "${FUCHSIA_DIR}/zircon/scripts/run-zircon" \
   -a "${FUCHSIA_ARCH}" \