diff --git a/init.zsh b/init.zsh
index 0e4c5d3..eed79b7 100644
--- a/init.zsh
+++ b/init.zsh
@@ -65,7 +65,9 @@ done
 
 # Set environment variables for launchd processes.
 if [[ "$OSTYPE" == darwin* ]]; then
-  launchctl setenv PATH "$PATH" &!
+  for env_var in PATH MANPATH; do
+    launchctl setenv "$env_var" "${(P)env_var}" &!
+  done
 fi
 
 # Load and run the prompt theming system.
diff --git a/plugins/osx/functions/manb b/plugins/osx/functions/manb
new file mode 100644
index 0000000..5dfb4c5
--- /dev/null
+++ b/plugins/osx/functions/manb
@@ -0,0 +1,18 @@
+# Open man pages in Bwana.
+function manb() {
+  local page
+  if (( $# > 0 )); then
+    for page in "$@"; do
+      open "man:$page" 2>/dev/null
+      if (( $? != 0 )); then
+        print "$0: Bwana is not installed" >&2
+        break
+      fi
+    done
+  else
+    print 'What manual page do you want?' >&2
+  fi
+}
+compdef _man manb
+manb "$@"
+