diff --git a/lib/grep.sh b/lib/grep.sh
index 5c2d1e9..af22c6d 100644
--- a/lib/grep.sh
+++ b/lib/grep.sh
@@ -7,16 +7,16 @@ grep_flag_available() {
 GREP_OPTIONS=""
 
 # color grep results
-if grep-flag-available --color=auto; then
+if grep_flag_available --color=auto; then
     GREP_OPTIONS+=( " --color=auto" )
 fi
 
 # ignore VCS folders (if the necessary grep flags are available)
 VCS_FOLDERS="{.bzr,CVS,.git,.hg,.svn}"
 
-if grep-flag-available --exclude-dir=.cvs; then
+if grep_flag_available --exclude-dir=.cvs; then
     GREP_OPTIONS+=( " --exclude-dir=$VCS_FOLDERS" )
-elif grep-flag-available --exclude=.cvs; then
+elif grep_flag_available --exclude=.cvs; then
     GREP_OPTIONS+=( " --exclude=$VCS_FOLDERS" )
 fi
 
diff --git a/lib/misc.sh b/lib/misc.sh
index ca7dc6a..b5de98a 100644
--- a/lib/misc.sh
+++ b/lib/misc.sh
@@ -23,4 +23,4 @@ if [[ -z "$LC_CTYPE" && -z "$LC_ALL" ]]; then
 fi
 
 # recognize comments
-shopt interactive_comments
+shopt -s interactive_comments