diff --git a/tests/runtest b/tests/runtest
index 042f2b6f..7a561625 100755
--- a/tests/runtest
+++ b/tests/runtest
@@ -1,7 +1,7 @@
 #!/bin/bash
 
 # check for command line arguments
-if [ -z $1 ] ; then
+if [ -z "$1" ] ; then
     echo "Usage: `basename $0` <test result file>"
     exit
 fi
@@ -33,7 +33,7 @@ echo
 echo "Running new test and storing result in $TARGETFILE ..."
 echo
 
-if [ -z $DMD ] ; then
+if [ -z "$DMD" ] ; then
 	echo "Testing with llvmdc. Set DMD environment variable to select compiler."
 	DMD="llvmdc -O0"
 else