diff --git a/README b/README
index 778989a..7de82a4 100644
--- a/README
+++ b/README
@@ -60,7 +60,7 @@ NOTES
               Set $_Z_NO_RESOLVE_SYMLINKS to prevent symlink resolution.
               Set $_Z_NO_PROMPT_COMMAND to handle PROMPT_COMMAND/precmd  your-
               self.
-              Set $_Z_EXCLUDE_DIRS to an array of directories to exclude.
+              Set $_Z_EXCLUDE_DIRS to an array of directory trees to  exclude.
               Set $_Z_OWNER to allow usage when in 'sudo -s' mode.
               (These  settings  should  go  in  .bashrc/.zshrc before the line
               added above.)
@@ -121,8 +121,8 @@ ENVIRONMENT
        to handle PROMPT_COMMAND or precmd yourself.
 
        The  environment  variable  $_Z_EXCLUDE_DIRS  can be set to an array of
-       directories to exclude from tracking. $HOME is always excluded.  Direc-
-       tories must be full paths without trailing slashes.
+       directory trees to exclude from tracking.  $HOME  is  always  excluded.
+       Directories must be full paths without trailing slashes.
 
        The  environment  variable  $_Z_OWNER  can  be set to your username, to
        allow usage of z when your sudo enviroment keeps $HOME set.
diff --git a/z.1 b/z.1
index bba9d78..cc99910 100644
--- a/z.1
+++ b/z.1
@@ -81,7 +81,7 @@ Set \fB$_Z_NO_RESOLVE_SYMLINKS\fR to prevent symlink resolution.
 Set \fB$_Z_NO_PROMPT_COMMAND\fR to handle \fBPROMPT_COMMAND/precmd\fR yourself.
 .RE
 .RS
-Set \fB$_Z_EXCLUDE_DIRS\fR to an array of directories to exclude.
+Set \fB$_Z_EXCLUDE_DIRS\fR to an array of directory trees to exclude.
 .RE
 .RS
 Set \fB$_Z_OWNER\fR to allow usage when in 'sudo -s' mode.
@@ -147,7 +147,7 @@ The environment variable \fB$_Z_NO_PROMPT_COMMAND\fR can be set if you want to
 handle \fBPROMPT_COMMAND\fR or \fBprecmd\fR yourself.
 .P
 The environment variable \fB$_Z_EXCLUDE_DIRS\fR can be set to an array of
-directories to exclude from tracking. \fB$HOME\fR is always excluded.
+directory trees to exclude from tracking. \fB$HOME\fR is always excluded.
 Directories must be full paths without trailing slashes.
 .P
 The environment variable \fB$_Z_OWNER\fR can be set to your username, to
diff --git a/z.sh b/z.sh
index a8c6a89..9510468 100644
--- a/z.sh
+++ b/z.sh
@@ -41,10 +41,10 @@ _z() {
         # $HOME isn't worth matching
         [ "$*" = "$HOME" ] && return
 
-        # don't track excluded dirs
+        # don't track excluded directory trees
         local exclude
         for exclude in "${_Z_EXCLUDE_DIRS[@]}"; do
-            [ "$*" = "$exclude" ] && return
+            case "$*" in $exclude*) return;; esac
         done
 
         # maintain the data file