diff --git a/test/Test/Iris.hs b/test/Test/Iris.hs
index 157f6ab..3c662dc 100644
--- a/test/Test/Iris.hs
+++ b/test/Test/Iris.hs
@@ -3,9 +3,10 @@ module Test.Iris (irisSpec) where
 import Test.Hspec (Spec, describe)
 
 import Test.Iris.Tool (toolSpec)
-import Test.Iris.Cli (cliSpec)
+import Test.Iris.Cli (cliSpec, cliSpecParserConflicts)
 
 irisSpec :: Spec
 irisSpec = describe "Iris" $ do
     toolSpec
     cliSpec
+    cliSpecParserConflicts
diff --git a/test/Test/Iris/Cli.hs b/test/Test/Iris/Cli.hs
index 5a7cd5d..8292203 100644
--- a/test/Test/Iris/Cli.hs
+++ b/test/Test/Iris/Cli.hs
@@ -1,15 +1,16 @@
 {-# LANGUAGE ScopedTypeVariables #-}
-module Test.Iris.Cli (cliSpec) where
+module Test.Iris.Cli (cliSpec, cliSpecParserConflicts) where
 
-import Test.Hspec (Spec, describe, it, shouldBe, expectationFailure, shouldReturn)
+import Test.Hspec (Expectation, Spec, describe, expectationFailure, it, shouldBe, shouldReturn)
 
+import Iris.Cli (VersionSettings (versionSettingsMkDesc))
+import Iris.Cli.Interactive (InteractiveMode (..), handleInteractiveMode)
+import Iris.Cli.Internal
 import Iris.Cli.ParserInfo (cmdParserInfo)
-import Iris.Settings (defaultCliEnvSettings, cliEnvSettingsVersionSettings)
 import Iris.Cli.Version (defaultVersionSettings)
+import Iris.Settings (CliEnvSettings (..), defaultCliEnvSettings)
 import qualified Options.Applicative as Opt
 import qualified Paths_iris as Autogen
-import Iris.Cli (VersionSettings(versionSettingsMkDesc))
-import Iris.Cli.Interactive (handleInteractiveMode, InteractiveMode (..))
 import System.Environment (lookupEnv)
 
 
@@ -51,17 +52,17 @@ cliSpec = describe "Cli Options" $ do
     it "help without version environment" $ do
         let parserInfo = cmdParserInfo defaultCliEnvSettings
         let result = Opt.execParserPure parserPrefs parserInfo ["--help"]
-        parseResultHandler result expectedHelpText
+        parseResultHandlerFailure result expectedHelpText
     it "help with version environment" $ do
         let cliEnvSettings = defaultCliEnvSettings { cliEnvSettingsVersionSettings = Just (defaultVersionSettings Autogen.version)}
-        let parserInfo= cmdParserInfo cliEnvSettings
+        let parserInfo = cmdParserInfo cliEnvSettings
         let result = Opt.execParserPure parserPrefs parserInfo ["--help"]
-        parseResultHandler result expectedHelpTextWithVersion
+        parseResultHandlerFailure result expectedHelpTextWithVersion
     it "--numeric-version returns correct version" $ do
         let cliEnvSettings = defaultCliEnvSettings { cliEnvSettingsVersionSettings = Just (defaultVersionSettings Autogen.version)}
-        let parserInfo= cmdParserInfo cliEnvSettings
+        let parserInfo = cmdParserInfo cliEnvSettings
         let result = Opt.execParserPure parserPrefs parserInfo ["--numeric-version"]
-        parseResultHandler result expectedNumericVersion
+        parseResultHandlerFailure result expectedNumericVersion
     it "CI interactivity check" $ do
         handleInteractiveMode NonInteractive `shouldReturn` NonInteractive
         isCi <- checkCI
@@ -70,16 +71,104 @@ cliSpec = describe "Cli Options" $ do
     it "--version returns correct version text" $ do
         let expectedVersionMkDescription = ("Version " ++)
         let cliEnvSettings = defaultCliEnvSettings { cliEnvSettingsVersionSettings = Just $ (defaultVersionSettings Autogen.version) {versionSettingsMkDesc  = expectedVersionMkDescription}}
-        let parserInfo= cmdParserInfo cliEnvSettings
+        let parserInfo = cmdParserInfo cliEnvSettings
         let expectedVersion = expectedVersionMkDescription expectedNumericVersion
         let result = Opt.execParserPure parserPrefs parserInfo ["--version"]
-        parseResultHandler result expectedVersion
-        where
-            parseResultHandler parseResult expected =
-                case parseResult of
-                    -- The help functionality is baked into optparse-applicative and presents itself as a ParserFailure.
-                    Opt.Failure (Opt.ParserFailure getFailure) -> do
-                        let (helpText, _exitCode, _int) = getFailure "<iris-test>"
-                        show helpText `shouldBe` expected
-                    Opt.Success _ -> expectationFailure "Expected 'Failure' but got Success "
-                    Opt.CompletionInvoked completionResult -> expectationFailure $ "Expected 'Failure' but got: " <> show completionResult
+        parseResultHandlerFailure result expectedVersion
+
+newtype UserDefinedParser a
+  = UserDefinedParser { noInteractive :: a }
+
+userDefinedNoInputOption :: Opt.Parser (UserDefinedParser String)
+userDefinedNoInputOption = UserDefinedParser
+      <$> Opt.strOption (Opt.long "no-input")
+
+userDefinedNoInputSwitch :: Opt.Parser (UserDefinedParser Bool)
+userDefinedNoInputSwitch = UserDefinedParser
+      <$> Opt.switch (Opt.long "no-input")
+
+userDefinedNoInputOnCommand :: Opt.Parser (UserDefinedParser Bool)
+userDefinedNoInputOnCommand = Opt.subparser
+       ( Opt.command "test-command"
+         (Opt.info userDefinedNoInputSwitch Opt.fullDesc))
+
+customParserSettings :: Opt.Parser (UserDefinedParser a) -> CliEnvSettings (UserDefinedParser a) ()
+customParserSettings parser = CliEnvSettings
+    { cliEnvSettingsCmdParser       = parser
+    , cliEnvSettingsAppEnv          = ()
+    , cliEnvSettingsHeaderDesc      = "Simple CLI program"
+    , cliEnvSettingsProgDesc        = "CLI tool build with iris - a Haskell CLI framework"
+    , cliEnvSettingsVersionSettings = Nothing
+    , cliEnvSettingsRequiredTools   = []
+    }
+
+argValue :: String
+argValue = "someValue"
+
+expectedErrorTextUserDefinedNoInputArg :: String
+expectedErrorTextUserDefinedNoInputArg =
+  "Invalid argument `" <> argValue <> "'\n\
+  \\n\
+  \Usage: <iris-test> [--no-input] --no-input ARG\n\
+  \\n\
+  \  CLI tool build with iris - a Haskell CLI framework"
+
+expectedErrorTextUserDefinedNoInputNoArg :: String
+expectedErrorTextUserDefinedNoInputNoArg =
+  "Missing: --no-input ARG\n\
+  \\n\
+  \Usage: <iris-test> [--no-input] --no-input ARG\n\
+  \\n\
+  \  CLI tool build with iris - a Haskell CLI framework"
+
+cliSpecParserConflicts :: Spec
+cliSpecParserConflicts = describe "Cli Parser Conflicts" $ do
+    let parserPrefs  = Opt.defaultPrefs
+    it "--no-input=someValue defined by user - arg provided" $ do
+        let parserInfo = cmdParserInfo $ customParserSettings userDefinedNoInputOption
+        let result = Opt.execParserPure parserPrefs parserInfo ["--no-input", argValue]
+        parseResultHandlerFailure result expectedErrorTextUserDefinedNoInputArg
+    it "--no-input=someValue defined by user - no arg provided" $ do
+        let parserInfo = cmdParserInfo $ customParserSettings userDefinedNoInputOption
+        let result = Opt.execParserPure parserPrefs parserInfo ["--no-input"]
+        parseResultHandlerFailure result expectedErrorTextUserDefinedNoInputNoArg
+    it "--no-input=someValue defined by user - not provided at all" $ do
+        let parserInfo = cmdParserInfo $ customParserSettings userDefinedNoInputOption
+        let result = Opt.execParserPure parserPrefs parserInfo []
+        parseResultHandlerFailure result expectedErrorTextUserDefinedNoInputNoArg
+    it "--no-input switch defined by user - provided" $ do
+        let parserInfo = cmdParserInfo $ customParserSettings userDefinedNoInputSwitch
+        let result = Opt.execParserPure parserPrefs parserInfo ["--no-input"]
+        parseResultHandlerSuccess result ["NonInteractive", "False"]
+    it "--no-input switch defined by user - not provided" $ do
+        let parserInfo = cmdParserInfo $ customParserSettings userDefinedNoInputSwitch
+        let result = Opt.execParserPure parserPrefs parserInfo []
+        parseResultHandlerSuccess result ["Interactive", "False"]
+    it "--no-input switch with command defined by user - user provided" $ do
+        let parserInfo = cmdParserInfo $ customParserSettings userDefinedNoInputOnCommand
+        let result = Opt.execParserPure parserPrefs parserInfo ["test-command", "--no-input"]
+        parseResultHandlerSuccess result ["Interactive", "True"]
+    it "--no-input switch with command defined by user - internal provided" $ do
+        let parserInfo = cmdParserInfo $ customParserSettings userDefinedNoInputOnCommand
+        let result = Opt.execParserPure parserPrefs parserInfo ["--no-input","test-command"]
+        parseResultHandlerSuccess result ["NonInteractive", "False"]
+
+parseResultHandlerSuccess :: Show b => Opt.ParserResult (Cmd (UserDefinedParser b)) -> [String] -> Expectation
+parseResultHandlerSuccess parseResult expected =
+    case parseResult of
+        Opt.Failure _ -> expectationFailure "Expected 'Success' but got 'Failure' "
+        Opt.Success a -> do
+            let internalNoInput = show $ cmdInteractiveMode a
+            let userDefinedNoInput = show . noInteractive . cmdCmd $ a
+            shouldBe [internalNoInput, userDefinedNoInput] expected
+        Opt.CompletionInvoked completionResult -> expectationFailure $ "Expected 'Success' but got: " <> show completionResult
+
+parseResultHandlerFailure :: Opt.ParserResult a -> String -> Expectation
+parseResultHandlerFailure parseResult expected =
+    case parseResult of
+        -- The help functionality is baked into optparse-applicative and presents itself as a ParserFailure.
+        Opt.Failure (Opt.ParserFailure getFailure) -> do
+            let (helpText, _exitCode, _int) = getFailure "<iris-test>"
+            show helpText `shouldBe` expected
+        Opt.Success _ -> expectationFailure "Expected 'Failure' but got 'Success' "
+        Opt.CompletionInvoked completionResult -> expectationFailure $ "Expected 'Failure' but got: " <> show completionResult