diff --git a/spec/ameba/cli/cmd_spec.cr b/spec/ameba/cli/cmd_spec.cr
index a412c194..624d1ad9 100644
--- a/spec/ameba/cli/cmd_spec.cr
+++ b/spec/ameba/cli/cmd_spec.cr
@@ -20,8 +20,14 @@ module Ameba::Cli
 
       %w(-c --config).each do |f|
         it "accepts #{f} flag" do
-          c = Cli.parse_args [f, "config.yml"]
-          c.config.should eq Path["config.yml"]
+          c = Cli.parse_args [f, "shard.yml"]
+          c.config.should eq Path["shard.yml"]
+        end
+
+        it "raises when config file doesn't exist" do
+          expect_raises(ArgumentError, "Unable to find config file foo.yml") do
+            Cli.parse_args [f, "foo.yml"]
+          end
         end
       end
 
diff --git a/src/ameba/cli/cmd.cr b/src/ameba/cli/cmd.cr
index d8ce4a7e..3b06b905 100644
--- a/src/ameba/cli/cmd.cr
+++ b/src/ameba/cli/cmd.cr
@@ -77,6 +77,8 @@ module Ameba::Cli
 
       parser.on("-c", "--config PATH",
         "Specify a configuration file") do |path|
+        raise ArgumentError.new("Unable to find config file #{path}") if !File.exists?(path) && !opts.skip_reading_config?
+
         opts.config = Path[path] unless path.empty?
       end