diff --git a/env/50_ruby.zsh b/env/50_ruby.zsh
index 4537e4a..8d73fad 100644
--- a/env/50_ruby.zsh
+++ b/env/50_ruby.zsh
@@ -1,2 +1,4 @@
-RUBY_VERSION=${$(gem environment gemdir):t}
-export PATH="$PATH:$HOME/.gem/ruby/$RUBY_VERSION/bin"
+if exists gem; then
+	RUBY_VERSION=${$(gem environment gemdir):t}
+	export PATH="$PATH:$HOME/.gem/ruby/$RUBY_VERSION/bin"
+fi
diff --git a/zshenv b/zshenv
index 7a689cd..fa0433f 100755
--- a/zshenv
+++ b/zshenv
@@ -1,5 +1,6 @@
 export ZDOTDIR="${$(readlink $HOME/.zshenv):h:a}"
 
+exists() { command -v "$@" >/dev/null }
 for i in $ZDOTDIR/env/*.zsh; do
 	. $i
 done