diff --git a/aliases b/aliases
new file mode 100644
index 0000000..af587e0
--- /dev/null
+++ b/aliases
@@ -0,0 +1,13 @@
+## .aliases
+
+case "$(uname)" in
+    "Darwin")
+        alias top="top -o cpu -s 5"
+        ;;
+    "Linux")
+        alias ls="ls --color"
+        ;;
+esac
+
+alias ll="ls -l"
+
diff --git a/bashrc b/bashrc
index 454fb0e..1bcc610 100644
--- a/bashrc
+++ b/bashrc
@@ -15,7 +15,5 @@ shopt -s cdspell
 # turn off bells
 set bell-style none
 
-#alias ls="ls --color"
-alias ll="ls -l"
-alias top="top -o cpu -s 5"
+source ~/.aliases
 
diff --git a/zshrc b/zshrc
index 9cf6abf..ec47a95 100644
--- a/zshrc
+++ b/zshrc
@@ -34,3 +34,5 @@ zstyle ':completion:*' verbose true
 zstyle ':completion:*:*:kill:*:processes' list-colors '=(#b) #([0-9]#)*=0=01;31'
 zstyle ':completion:*:kill:*' command 'ps -u $USER -o pid,%cpu,tty,cputime,cmd'
 
+source ~/.aliases
+