diff --git a/spring-shell-core/src/main/java/org/springframework/shell/command/CommandParser.java b/spring-shell-core/src/main/java/org/springframework/shell/command/CommandParser.java
index 2abfa295..099559ce 100644
--- a/spring-shell-core/src/main/java/org/springframework/shell/command/CommandParser.java
+++ b/spring-shell-core/src/main/java/org/springframework/shell/command/CommandParser.java
@@ -22,6 +22,7 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.Deque;
 import java.util.List;
+import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -213,7 +214,15 @@ public interface CommandParser {
 				.filter(o -> o.isRequired())
 				.collect(Collectors.toList());
 
-			Lexer lexer = new Lexer(args);
+			Set<String> splitValidValues = options.stream()
+				.flatMap(o -> {
+					Stream<String> longs = Stream.of(o.getLongNames()).map(l -> "--" + l);
+					Stream<String> shorts = Stream.of(o.getShortNames()).map(s -> "-"+ Character.toString(s));
+					return Stream.concat(longs, shorts);
+				})
+				.collect(Collectors.toSet());
+
+			Lexer lexer = new Lexer(args, splitValidValues);
 			List<List<String>> lexerResults = lexer.visit();
 			Parser parser = new Parser();
 			ParserResults parserResults = parser.visit(lexerResults, options);
@@ -228,7 +237,7 @@ public interface CommandParser {
 				}
 				else {
 					for (String arg : pr.args) {
-						if (arg.startsWith("-")) {
+						if (arg.startsWith("--")) {
 							errors.add(UnrecognisedOptionException.of(String.format("Unrecognised option '%s'", arg),
 									arg));
 						}
@@ -520,11 +529,13 @@ public interface CommandParser {
 		 */
 		private static class Lexer {
 			private final String[] args;
-			Lexer(String[] args) {
+			private final Set<String> splitValidValues;
+			Lexer(String[] args, Set<String> splitValues) {
 				this.args = args;
+				this.splitValidValues = splitValues;
 			}
 			List<List<String>> visit() {
-				return Utils.split(args, t -> t.startsWith("-"));
+				return Utils.split(args, t -> splitValidValues.contains(t));
 			}
 		}
 	}
diff --git a/spring-shell-core/src/test/java/org/springframework/shell/command/CommandParserTests.java b/spring-shell-core/src/test/java/org/springframework/shell/command/CommandParserTests.java
index 01614a8b..732a439d 100644
--- a/spring-shell-core/src/test/java/org/springframework/shell/command/CommandParserTests.java
+++ b/spring-shell-core/src/test/java/org/springframework/shell/command/CommandParserTests.java
@@ -26,8 +26,10 @@ import org.springframework.core.ResolvableType;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.shell.command.CommandParser.CommandParserResults;
+import org.springframework.shell.command.CommandParser.MissingOptionException;
 import org.springframework.shell.command.CommandParser.NotEnoughArgumentsOptionException;
 import org.springframework.shell.command.CommandParser.TooManyArgumentsOptionException;
+import org.springframework.shell.command.CommandParser.UnrecognisedOptionException;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -496,6 +498,11 @@ public class CommandParserTests extends AbstractCommandTests {
 		CommandParserResults results = parser.parse(options, args);
 		assertThat(results.results()).hasSize(0);
 		assertThat(results.errors()).hasSize(1);
+		assertThat(results.errors()).satisfiesExactly(
+			e -> {
+				assertThat(e).isInstanceOf(UnrecognisedOptionException.class);
+			}
+		);
 		assertThat(results.positional()).hasSize(1);
 	}
 
@@ -508,6 +515,11 @@ public class CommandParserTests extends AbstractCommandTests {
 		CommandParserResults results = parser.parse(options, args);
 		assertThat(results.results()).hasSize(1);
 		assertThat(results.errors()).hasSize(1);
+		assertThat(results.errors()).satisfiesExactly(
+			e -> {
+				assertThat(e).isInstanceOf(UnrecognisedOptionException.class);
+			}
+		);
 		assertThat(results.positional()).hasSize(1);
 	}
 
@@ -520,9 +532,29 @@ public class CommandParserTests extends AbstractCommandTests {
 		CommandParserResults results = parser.parse(options, args);
 		assertThat(results.results()).hasSize(0);
 		assertThat(results.errors()).hasSize(2);
+		assertThat(results.errors()).satisfiesExactly(
+			e -> {
+				assertThat(e).isInstanceOf(UnrecognisedOptionException.class);
+			},
+			e -> {
+				assertThat(e).isInstanceOf(MissingOptionException.class);
+			}
+		);
 		assertThat(results.positional()).hasSize(1);
 	}
 
+	@Test
+	public void testDashOptionValueDoNotError() {
+		// gh-651
+		CommandOption option1 = longOption("arg1");
+		List<CommandOption> options = Arrays.asList(option1);
+		String[] args = new String[]{"--arg1", "-1"};
+		CommandParserResults results = parser.parse(options, args);
+		assertThat(results.results()).hasSize(1);
+		assertThat(results.errors()).hasSize(0);
+		assertThat(results.positional()).hasSize(0);
+	}
+
 	@Test
 	public void testPositionDoesNotAffectRequiredErrorWithOtherErrors() {
 		// gh-601