diff --git a/spec/lucky_env_spec.cr b/spec/lucky_env_spec.cr
index 33ad3a5..c0d2ff4 100644
--- a/spec/lucky_env_spec.cr
+++ b/spec/lucky_env_spec.cr
@@ -1,5 +1,11 @@
 require "./spec_helper"
 
+# The default environments are configured to look for Lucky-specific environment
+# files. We redefine them here for testing purposes.
+LuckyEnv.add_env :development, env_file: "./spec/support/.env"
+LuckyEnv.add_env :production, env_file: "./spec/support/.env.production"
+LuckyEnv.add_env :test, env_file: "./spec/support/.env.test"
+
 describe LuckyEnv do
   original_env = ENV.to_h
 
@@ -25,6 +31,36 @@ describe LuckyEnv do
       ENV["LUCKY_ENV"].should eq "test"
       ENV["DEV_PORT"].should eq "3500"
     end
+
+    context "when no file path is provided" do
+      it "reads the environment file based on the current environment" do
+        ENV["LUCKY_ENV"] = "development"
+        LuckyEnv.load
+        ENV["ENV_FILE"]?.should eq(".env")
+
+        ENV["LUCKY_ENV"] = "production"
+        LuckyEnv.load
+        ENV["ENV_FILE"]?.should eq(".env.production")
+
+        ENV["LUCKY_ENV"] = "test"
+        LuckyEnv.load
+        ENV["ENV_FILE"]?.should eq(".env.test")
+      end
+
+      context "when environment does not exist" do
+        it "raises an error" do
+          ENV["LUCKY_ENV"] = "staging"
+          expected_msg = <<-MSG
+          Unknown environment staging. Have you forgotten to add it?
+
+          LuckyEnv.add_env :staging, env_file: File.expand_path(".env.staging")
+          MSG
+          expect_raises(LuckyEnv::UnknownEnvironmentError, expected_msg) do
+            LuckyEnv.load
+          end
+        end
+      end
+    end
   end
 
   describe "load?" do
@@ -40,6 +76,29 @@ describe LuckyEnv do
       data["LUCKY_ENV"].should eq "test"
       ENV["LUCKY_ENV"].should eq "test"
     end
+
+    context "when no file path is provided" do
+      it "reads the environment file based on the current environment" do
+        ENV["LUCKY_ENV"] = "development"
+        LuckyEnv.load?
+        ENV["ENV_FILE"]?.should eq(".env")
+
+        ENV["LUCKY_ENV"] = "production"
+        LuckyEnv.load?
+        ENV["ENV_FILE"]?.should eq(".env.production")
+
+        ENV["LUCKY_ENV"] = "test"
+        LuckyEnv.load?
+        ENV["ENV_FILE"]?.should eq(".env.test")
+      end
+
+      context "when environment does not exist" do
+        it "returns nil" do
+          ENV["LUCKY_ENV"] = "staging"
+          LuckyEnv.load?.should be_nil
+        end
+      end
+    end
   end
 
   describe ".development?" do
diff --git a/spec/support/.env b/spec/support/.env
index 39709e4..9d8192c 100644
--- a/spec/support/.env
+++ b/spec/support/.env
@@ -4,3 +4,4 @@ DEV_PORT=3500
 SECRET_KEY_BASE=j5I0VrpzT1Of7dhCA=
 ASSET_HOST="https://luckyframework.org"
 ENV_WITH_SPACE= start_end 
+ENV_FILE=".env"
diff --git a/spec/support/.env.production b/spec/support/.env.production
new file mode 100644
index 0000000..7128194
--- /dev/null
+++ b/spec/support/.env.production
@@ -0,0 +1,2 @@
+LUCKY_ENV=production
+ENV_FILE=.env.production
diff --git a/spec/support/.env.test b/spec/support/.env.test
index a855296..ad9c48c 100644
--- a/spec/support/.env.test
+++ b/spec/support/.env.test
@@ -1 +1,2 @@
 LUCKY_ENV=test
+ENV_FILE=.env.test
diff --git a/spec/support/production_env b/spec/support/production_env
deleted file mode 100644
index 4a982c7..0000000
--- a/spec/support/production_env
+++ /dev/null
@@ -1 +0,0 @@
-LUCKY_ENV=production
diff --git a/src/lucky_env.cr b/src/lucky_env.cr
index 591ea44..c0e6f42 100644
--- a/src/lucky_env.cr
+++ b/src/lucky_env.cr
@@ -3,14 +3,35 @@ require "./lucky_env/string_modifier"
 require "./lucky_env/*"
 
 module LuckyEnv
-  VERSION = {{ `shards version "#{__DIR__}"`.chomp.stringify }}
+  VERSION      = {{ `shards version "#{__DIR__}"`.chomp.stringify }}
+  ENVIRONMENTS = {} of String => String
 
-  macro add_env(name)
+  macro add_env(name, env_file)
+    LuckyEnv::ENVIRONMENTS[{{ name.id.stringify }}] = {{ env_file }}
+
+    # Check if the current `environment` is `{{ name.id.stringify }}`.
     def LuckyEnv.{{ name.id }}?
       environment == {{ name.id.stringify }}
     end
   end
 
+  # Load the results of parsing the env file associated with the current Lucky
+  # `environment` (see `add_env`) in to `ENV`.
+  #
+  # If the environment is unknown, it raises an `UnknownEnvironmentError`.
+  # If the associated env file does not exist, it raises a `MissingFileError`.
+  def self.load : Hash(String, String)
+    if ENVIRONMENTS.has_key?(environment)
+      load(ENVIRONMENTS[environment])
+    else
+      raise UnknownEnvironmentError.new <<-ERROR
+      Unknown environment #{environment}. Have you forgotten to add it?
+
+      LuckyEnv.add_env :#{environment}, env_file: File.expand_path(".env.#{environment}")
+      ERROR
+    end
+  end
+
   # Parses the `file_path`, and loads the results in to `ENV`
   # raises `LuckyEnv::MissingFileError` if the file is missing
   def self.load(file_path : String) : Hash(String, String)
@@ -23,6 +44,15 @@ module LuckyEnv
     data
   end
 
+  # Load the results of parsing the env file associated with the current Lucky
+  # `environment` (see `add_env`) in to `ENV`.
+  #
+  # If the environment is unknown or the associated env file does not exist, it
+  # returns `Nil`.
+  def self.load? : Hash(String, String)?
+    load?(ENVIRONMENTS[environment]) if ENVIRONMENTS.has_key?(environment)
+  end
+
   # Returns `nil` if the file is missing
   def self.load?(file_path : String) : Hash(String, String)?
     if File.exists?(file_path) || File.symlink?(file_path)
@@ -30,15 +60,20 @@ module LuckyEnv
     end
   end
 
+  # Check if a [LuckyTask](https://github.com/luckyframework/lucky_task) is
+  # currently running.
   def self.task?
     ENV["LUCKY_TASK"] == "true" || ENV["LUCKY_TASK"] == "1"
   end
 
+  # Returns the current Lucky environment (`ENV["LUCKY_ENV"]`).
+  #
+  # If `ENV["LUCKY_ENV"]` is not set, it defaults to `"development"`.
   def self.environment
     ENV.fetch("LUCKY_ENV", "development")
   end
 
-  add_env :development
-  add_env :production
-  add_env :test
+  add_env :development, env_file: File.expand_path(".env")
+  add_env :production, env_file: File.expand_path(".env.production")
+  add_env :test, env_file: File.expand_path(".env.test")
 end
diff --git a/src/lucky_env/errors.cr b/src/lucky_env/errors.cr
index 37aaefb..06291c0 100644
--- a/src/lucky_env/errors.cr
+++ b/src/lucky_env/errors.cr
@@ -4,4 +4,7 @@ module LuckyEnv
 
   class MissingFileError < Exception
   end
+
+  class UnknownEnvironmentError < Exception
+  end
 end