diff --git a/spring-shell-core/src/main/java/org/springframework/shell/command/parser/Lexer.java b/spring-shell-core/src/main/java/org/springframework/shell/command/parser/Lexer.java
index bb01ad9d2..04a002cc4 100644
--- a/spring-shell-core/src/main/java/org/springframework/shell/command/parser/Lexer.java
+++ b/spring-shell-core/src/main/java/org/springframework/shell/command/parser/Lexer.java
@@ -222,7 +222,13 @@ else if (isLastTokenOfType(tokenList, TokenType.COMMAND)) {
 					}
 				}
 				else if (isLastTokenOfType(tokenList, TokenType.ARGUMENT)) {
-					tokenList.add(Token.of(argument, TokenType.ARGUMENT, i2));
+					int decuceArgumentStyle = decuceArgumentStyle(argument);
+					if (decuceArgumentStyle < 0) {
+						tokenList.add(Token.of(argument, TokenType.ARGUMENT, i2));
+					}
+					else {
+						tokenList.add(Token.of(argument, TokenType.OPTION, i2));
+					}
 				}
 
 			}
diff --git a/spring-shell-core/src/test/java/org/springframework/shell/command/parser/AbstractParsingTests.java b/spring-shell-core/src/test/java/org/springframework/shell/command/parser/AbstractParsingTests.java
index c54e0b52b..fe5b2a580 100644
--- a/spring-shell-core/src/test/java/org/springframework/shell/command/parser/AbstractParsingTests.java
+++ b/spring-shell-core/src/test/java/org/springframework/shell/command/parser/AbstractParsingTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 the original author or authors.
+ * Copyright 2023-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -416,4 +416,11 @@ ParseResult parse(ParserConfig config, String... arguments) {
 		Parser parser = new Parser.DefaultParser(commandModel, lexer(config), ast, config);
 		return parser.parse(Arrays.asList(arguments));
 	}
+
+	record RegAndArgs(CommandRegistration reg, String... args) {
+		static RegAndArgs of(CommandRegistration reg, String... args) {
+			return new RegAndArgs(reg, args);
+		}
+	}
+
 }
diff --git a/spring-shell-core/src/test/java/org/springframework/shell/command/parser/LexerTests.java b/spring-shell-core/src/test/java/org/springframework/shell/command/parser/LexerTests.java
index 8cc82302a..87f633d35 100644
--- a/spring-shell-core/src/test/java/org/springframework/shell/command/parser/LexerTests.java
+++ b/spring-shell-core/src/test/java/org/springframework/shell/command/parser/LexerTests.java
@@ -274,6 +274,38 @@ void notDefinedOptionShouldBeOptionAfterDefinedOption() {
 				});
 	}
 
+	@Test
+	void notDefinedOptionShouldBeOptionAfterDefinedOptionHavingArgument() {
+		register(ROOT3);
+		List<Token> tokens = tokenize("root3", "--arg1", "value1", "--arg2");
+
+		assertThat(tokens).satisfiesExactly(
+				token -> {
+					ParserAssertions.assertThat(token)
+						.isType(TokenType.COMMAND)
+						.hasPosition(0)
+						.hasValue("root3");
+				},
+				token -> {
+					ParserAssertions.assertThat(token)
+						.isType(TokenType.OPTION)
+						.hasPosition(1)
+						.hasValue("--arg1");
+				},
+				token -> {
+					ParserAssertions.assertThat(token)
+						.isType(TokenType.ARGUMENT)
+						.hasPosition(2)
+						.hasValue("value1");
+				},
+				token -> {
+					ParserAssertions.assertThat(token)
+						.isType(TokenType.OPTION)
+						.hasPosition(3)
+						.hasValue("--arg2");
+				});
+	}
+
 	@Test
 	void optionsWithoutValuesFromRoot() {
 		register(ROOT5);
diff --git a/spring-shell-core/src/test/java/org/springframework/shell/command/parser/ParserTests.java b/spring-shell-core/src/test/java/org/springframework/shell/command/parser/ParserTests.java
index 511ba33cc..5ec3a1759 100644
--- a/spring-shell-core/src/test/java/org/springframework/shell/command/parser/ParserTests.java
+++ b/spring-shell-core/src/test/java/org/springframework/shell/command/parser/ParserTests.java
@@ -15,8 +15,12 @@
  */
 package org.springframework.shell.command.parser;
 
+import java.util.stream.Stream;
+
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 
 import org.springframework.shell.command.parser.Parser.ParseResult;
 import org.springframework.shell.command.parser.ParserConfig.Feature;
@@ -161,6 +165,31 @@ void shouldHaveErrorResult2() {
 			);
 		}
 
+		static Stream<RegAndArgs> shouldHaveErrorForUnrecognisedOption() {
+			return Stream.of(
+				RegAndArgs.of(ROOT1, "root1", "--arg1"),
+				RegAndArgs.of(ROOT3, "root3", "--arg2", "--arg1"),
+				RegAndArgs.of(ROOT3, "root3", "--arg1", "--arg2"),
+				RegAndArgs.of(ROOT3, "root3", "--arg2", "fake1", "--arg1"),
+				RegAndArgs.of(ROOT3, "root3", "--arg1", "--arg2", "fake1"),
+				RegAndArgs.of(ROOT3, "root3", "--arg2", "fake1", "--arg1", "fake2"),
+				RegAndArgs.of(ROOT3, "root3", "--arg1", "fake2", "--arg2", "fake1")
+				);
+		}
+
+		@ParameterizedTest
+		@MethodSource
+		void shouldHaveErrorForUnrecognisedOption(RegAndArgs regAndArgs) {
+			register(regAndArgs.reg());
+			ParseResult result = parse(regAndArgs.args());
+			assertThat(result.messageResults()).satisfiesExactlyInAnyOrder(
+				message -> {
+					ParserAssertions.assertThat(message.parserMessage()).hasCode(2001).hasType(ParserMessage.Type.ERROR);
+				}
+			);
+
+		}
+
 		@Test
 		void lexerMessageShouldGetPropagated() {
 			ParseResult parse = parse("--");