diff --git a/src/rebar.erl b/src/rebar.erl
index 2a23bff..a103d29 100644
--- a/src/rebar.erl
+++ b/src/rebar.erl
@@ -135,6 +135,9 @@ parse_args(Args) ->
             %% Check options and maybe halt execution
             ok = show_info_maybe_halt(Options, NonOptArgs),
 
+            GlobalDefines = proplists:get_all_values(defines, Options),
+            rebar_config:set_global(defines, GlobalDefines),
+
             %% Set global variables based on getopt options
             set_global_flag(Options, verbose),
             set_global_flag(Options, force),
@@ -263,6 +266,7 @@ option_spec_list() ->
      {verbose,  $v, "verbose",  undefined, "Be verbose about what gets done"},
      {version,  $V, "version",  undefined, "Show version information"},
      {force,    $f, "force",    undefined, "Force"},
+     {defines,  $D, undefined,   string,    "Define compiler macro"},
      {jobs,     $j, "jobs",     integer,   JobsHelp},
      {config,   $C, "config",   string,    "Rebar config file to use"}
     ].
diff --git a/src/rebar_erlc_compiler.erl b/src/rebar_erlc_compiler.erl
index 9611097..447cb7c 100644
--- a/src/rebar_erlc_compiler.erl
+++ b/src/rebar_erlc_compiler.erl
@@ -122,14 +122,8 @@ doterl_compile(Config, OutDir) ->
 
 doterl_compile(Config, OutDir, MoreSources) ->
     FirstErls = rebar_config:get_list(Config, erl_first_files, []),
-    RawErlOpts = filter_defines(rebar_config:get(Config, erl_opts, []), []),
-    ErlOpts = case proplists:is_defined(no_debug_info, RawErlOpts) of
-                  true ->
-                      [O || O <- RawErlOpts, O =/= no_debug_info];
-                  _ ->
-                      [debug_info|RawErlOpts]
-              end,
-    ?DEBUG("erl_opts ~p~n",[ErlOpts]),
+    ErlOpts = erl_opts(Config),
+    ?DEBUG("erl_opts ~p~n", [ErlOpts]),
     %% Support the src_dirs option allowing multiple directories to
     %% contain erlang source. This might be used, for example, should
     %% eunit tests be separated from the core application source.
@@ -170,6 +164,18 @@ doterl_compile(Config, OutDir, MoreSources) ->
 %% Internal functions
 %% ===================================================================
 
+erl_opts(Config) ->
+    RawErlOpts = filter_defines(rebar_config:get(Config, erl_opts, []), []),
+    GlobalDefines = lists:map(fun(D) -> list_to_atom(D) end,
+                              rebar_config:get_global(defines, [])),
+    Opts = GlobalDefines ++ RawErlOpts,
+    case proplists:is_defined(no_debug_info, Opts) of
+        true ->
+            [O || O <- Opts, O =/= no_debug_info];
+        _ ->
+            [debug_info|Opts]
+    end.
+
 -spec include_path(Source::file:filename(),
                    Config::rebar_config:config()) -> [file:filename(), ...].
 include_path(Source, Config) ->