diff --git a/cmdarg.sh b/cmdarg.sh
index 7072446..4e275ea 100644
--- a/cmdarg.sh
+++ b/cmdarg.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-bashversion=$(bash --version | head -n 1 | grep "version [0-9]" | cut -d ' ' -f 2)
+bashversion=$(bash --version | head -n 1 | grep -o "version [0-9]" | cut -d ' ' -f 2)
 if [ $bashversion -lt 4 ]; then
     echo "cmdarg is incompatible with bash versions < 4.0, please upgrade bash" >&2
     exit 1