diff --git a/soong.bash b/soong.bash
index b282a1e..778f5e0 100755
--- a/soong.bash
+++ b/soong.bash
@@ -3,24 +3,24 @@
 # Determine the build directory location based on the location of this script.
 BPBUILD="${BASH_SOURCE[0]}"
 BUILDDIR=`dirname "${BASH_SOURCE[0]}"`
-BOOTSTRAP=${BUILDDIR}/.soong.bootstrap
+BOOTSTRAP="${BUILDDIR}/.soong.bootstrap"
 
 # The source directory path and operating system will get written to
 # .soong.bootstrap by the bootstrap script.
 
-if [ ! -f ${BOOTSTRAP} ]; then
+if [ ! -f "${BOOTSTRAP}" ]; then
     echo "Error: soong script must be located in a directory created by bootstrap.bash"
     exit 1
 fi
 
-source ${BOOTSTRAP}
+source "${BOOTSTRAP}"
 
 if [[ ${SRCDIR_IN:0:1} == '/' ]]; then
     # SRCDIR_IN is an absolute path
-    SRCDIR=${SRCDIR_IN}
+    SRCDIR="${SRCDIR_IN}"
 else
     # SRCDIR_IN is a relative path
-    SRCDIR=${BUILDDIR}/${SRCDIR_IN}
+    SRCDIR="${BUILDDIR}/${SRCDIR_IN}"
 fi
 
 # Let Blueprint know that the Ninja we're using performs multiple passes that
@@ -30,18 +30,18 @@
 # Ninja can't depend on environment variables, so do a manual comparison
 # of the relevant environment variables from the last build using the
 # soong_env tool and trigger a build manifest regeneration if necessary
-ENVFILE=${BUILDDIR}/.soong.environment
-ENVTOOL=${BUILDDIR}/.bootstrap/bin/soong_env
-if [ -f ${ENVFILE} ]; then
-    if [ -x ${ENVTOOL} ]; then
-        if ! ${ENVTOOL} ${ENVFILE}; then
+ENVFILE="${BUILDDIR}/.soong.environment"
+ENVTOOL="${BUILDDIR}/.bootstrap/bin/soong_env"
+if [ -f "${ENVFILE}" ]; then
+    if [ -x "${ENVTOOL}" ]; then
+        if ! "${ENVTOOL}" "${ENVFILE}"; then
             echo "forcing build manifest regeneration"
-            rm -f ${ENVFILE}
+            rm -f "${ENVFILE}"
         fi
     else
         echo "Missing soong_env tool, forcing build manifest regeneration"
-        rm -f ${ENVFILE}
+        rm -f "${ENVFILE}"
     fi
 fi
 
-${SRCDIR}/prebuilts/ninja/${PREBUILTOS}/ninja -C ${BUILDDIR} "$@"
+"${SRCDIR}/prebuilts/ninja/${PREBUILTOS}/ninja" -C "${BUILDDIR}" "$@"