diff --git a/.tool-versions b/.tool-versions
index 58bf1ce..fde38bd 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,2 +1,2 @@
-elixir 1.4.0
-erlang 19.1
+elixir 1.7.0
+erlang 21.0
diff --git a/.travis.yml b/.travis.yml
index 9f50ef1..2180e42 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,19 +1,31 @@
 language: elixir
 elixir:
-  - 1.2.6
   - 1.3.4
   - 1.4.5
-  - 1.5.0
+  - 1.5.3
+  - 1.6.6
+  - 1.7.0
 otp_release:
   - 18.3
   - 19.3
-  - 20.0
+  - 20.3
+  - 21.0
 matrix:
   exclude:
     - elixir: 1.3.4
-      otp_release: 20.0
-    - elixir: 1.2.6
-      otp_release: 20.0
+      otp_release: 20.3
+    - elixir: 1.3.4
+      otp_release: 21.0
+    - elixir: 1.4.5
+      otp_release: 21.0
+    - elixir: 1.5.3
+      otp_release: 21.0
+    - elixir: 1.6.6
+      otp_release: 18.3
+    - elixir: 1.7.0
+      otp_release: 18.3
+    - elixir: 1.7.0
+      otp_release: 19.3
 before_script: MIX_ENV=test mix compile --warnings-as-errors
 script: mix coveralls.travis
 after_script:
diff --git a/mix.exs b/mix.exs
index 1187339..09eb739 100644
--- a/mix.exs
+++ b/mix.exs
@@ -14,7 +14,7 @@ defmodule DeepMerge.Mixfile do
      docs: [source_ref: @version],
      test_coverage: [tool: ExCoveralls],
      preferred_cli_env: [
-       "coveralls": :test, "coveralls.detail": :test,
+       coveralls: :test, "coveralls.detail": :test,
        "coveralls.post": :test, "coveralls.html": :test,
        "coveralls.travis": :test],
      package: package(),