diff --git a/REQUIRE b/REQUIRE
index 94237c0..137767a 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1 +1 @@
-julia 0.5
+julia 0.6
diff --git a/src/TerminalExtensions.jl b/src/TerminalExtensions.jl
index abe4c8a..7daaf11 100644
--- a/src/TerminalExtensions.jl
+++ b/src/TerminalExtensions.jl
@@ -34,7 +34,7 @@ module iTerm2
 
     import Base: display
 
-    immutable InlineDisplay <: Display; end
+    struct InlineDisplay <: Display; end
 
     function set_mark()
         "\033]50;SetMark\007"