diff --git a/debian/flif.bash-completion b/debian/flif.bash-completion
index fa90f106..0fa49139 100644
--- a/debian/flif.bash-completion
+++ b/debian/flif.bash-completion
@@ -10,7 +10,7 @@ _flif()
     base_name=output
 
     # scan the previous arguments to guess what we are doing: encoding or decoding?
-    for pw in ${words[@]:1:$(($cword - 1))}; do
+    for pw in "${words[@]:1:$((cword - 1))}"; do
         case $pw in
             -d|--decode)
                 action=decode
@@ -35,8 +35,8 @@ _flif()
                     unknown|decode)
                         action=decode
                         base_name=$pw
-                        base_name=$(basename $base_name .flif)
-                        base_name=$(basename $base_name .flf)
+                        base_name=$(basename "$base_name" .flif)
+                        base_name=$(basename "$base_name" .flf)
                         case $next_arg_needed in
                             flif|unknown)
                                 next_arg_needed=nonflif
@@ -52,8 +52,8 @@ _flif()
                             flif)
                                 next_arg_needed=flif2
                                 base_name=$pw
-                                base_name=$(basename $base_name .flif)
-                                base_name=$(basename $base_name .flf)
+                                base_name=$(basename "$base_name" .flif)
+                                base_name=$(basename "$base_name" .flf)
                                 base_name="$base_name-transcoded"
                                 ;;
                             flif2)
@@ -72,13 +72,13 @@ _flif()
                         action=encode
                         next_arg_needed=flif
                         base_name=$pw
-                        base_name=$(basename $base_name .png)
-                        base_name=$(basename $base_name .pnm)
-                        base_name=$(basename $base_name .pam)
-                        base_name=$(basename $base_name .ppm)
-                        base_name=$(basename $base_name .pgm)
-                        base_name=$(basename $base_name .pbm)
-                        base_name=$(basename $base_name .rggb)
+                        base_name=$(basename "$base_name" .png)
+                        base_name=$(basename "$base_name" .pnm)
+                        base_name=$(basename "$base_name" .pam)
+                        base_name=$(basename "$base_name" .ppm)
+                        base_name=$(basename "$base_name" .pgm)
+                        base_name=$(basename "$base_name" .pbm)
+                        base_name=$(basename "$base_name" .rggb)
                         ;;
                     decode)
                         next_arg_needed=none