diff --git a/bin/build-docs.sh b/bin/build-docs.sh
index cfade88..e0e2800 100755
--- a/bin/build-docs.sh
+++ b/bin/build-docs.sh
@@ -16,7 +16,7 @@ inputDir="docs/en"
 outputArg="${1}"
 firstChar=$(echo "$1" | cut -c1-1)
 
-if [ "$firstChar" != "/" ]
+if [ "$firstChar" != "/" ] && [ "$firstChar" != "" ]
 then
   # Output directory should be relative to working directory
   outputArg="$rootDir/$outputArg"