diff --git a/lib/iruby/kernel_app.rb b/lib/iruby/kernel_app.rb
index 98b96b0..9210e65 100644
--- a/lib/iruby/kernel_app.rb
+++ b/lib/iruby/kernel_app.rb
@@ -50,13 +50,13 @@ def run
         if argv.length <= 3
           @connection_file, @boot_file, @work_dir = argv
         else
-          raise ArgumentError, "Too many comandline arguments"
+          raise ArgumentError, "Too many commandline arguments"
         end
       else
         if argv.length <= 2
           @boot_file, @work_dir = argv
         else
-          raise ArgumentError, "Too many comandline arguments"
+          raise ArgumentError, "Too many commandline arguments"
         end
       end
 
diff --git a/test/iruby/application/register_test.rb b/test/iruby/application/register_test.rb
index f7ad9b4..bc7b3a4 100644
--- a/test/iruby/application/register_test.rb
+++ b/test/iruby/application/register_test.rb
@@ -32,7 +32,7 @@ def setup
         end
       end
 
-      test("IRuby warns tthe existence of the kernel in IPython's kerenls directory and executes `jupyter kernelspec install` command") do
+      test("IRuby warns the existence of the kernel in IPython's kernels directory and executes `jupyter kernelspec install` command") do
         out, status = Open3.capture2e(*iruby_command("register"))
         assert status.success?
         assert_match(/^Fake Jupyter$/, out)