diff --git a/cloud-annotations/src/main/java/cloud/commandframework/annotations/SyntaxParser.java b/cloud-annotations/src/main/java/cloud/commandframework/annotations/SyntaxParser.java
index ab13e34c..c4534e91 100644
--- a/cloud-annotations/src/main/java/cloud/commandframework/annotations/SyntaxParser.java
+++ b/cloud-annotations/src/main/java/cloud/commandframework/annotations/SyntaxParser.java
@@ -38,11 +38,11 @@ import java.util.regex.Pattern;
  */
 final class SyntaxParser implements Function<@NonNull String, @NonNull List<@NonNull SyntaxFragment>> {
 
-    private static final Predicate<String> PATTERN_ARGUMENT_LITERAL = Pattern.compile("([A-Za-z0-9]+)(|([A-Za-z0-9]+))*")
+    private static final Predicate<String> PATTERN_ARGUMENT_LITERAL = Pattern.compile("([A-Za-z0-9\\-_]+)(|([A-Za-z0-9\\-_]+))*")
             .asPredicate();
-    private static final Predicate<String> PATTERN_ARGUMENT_REQUIRED = Pattern.compile("<([A-Za-z0-9]+)>")
+    private static final Predicate<String> PATTERN_ARGUMENT_REQUIRED = Pattern.compile("<([A-Za-z0-9\\-_]+)>")
             .asPredicate();
-    private static final Predicate<String> PATTERN_ARGUMENT_OPTIONAL = Pattern.compile("\\[([A-Za-z0-9]+)]")
+    private static final Predicate<String> PATTERN_ARGUMENT_OPTIONAL = Pattern.compile("\\[([A-Za-z0-9\\-_]+)]")
             .asPredicate();
 
     @Override
diff --git a/cloud-annotations/src/test/java/cloud/commandframework/annotations/SyntaxParserTest.java b/cloud-annotations/src/test/java/cloud/commandframework/annotations/SyntaxParserTest.java
new file mode 100644
index 00000000..f59c4bf8
--- /dev/null
+++ b/cloud-annotations/src/test/java/cloud/commandframework/annotations/SyntaxParserTest.java
@@ -0,0 +1,107 @@
+//
+// MIT License
+//
+// Copyright (c) 2020 Alexander Söderberg & Contributors
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+package cloud.commandframework.annotations;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests the correct functioning of the {@link SyntaxParser}, which parses
+ * command syntax into a List of {@link SyntaxFragment}
+ */
+public class SyntaxParserTest {
+
+    @Test
+    void testParseWithAliases() {
+        List<SyntaxFragment> fragments = new SyntaxParser().apply(
+                "literal|litalias1|litalias2 <requirement> [optional]");
+
+        Assertions.assertEquals(3, fragments.size());
+
+        final SyntaxFragment literal = fragments.get(0);
+        Assertions.assertEquals("literal", literal.getMajor());
+        Assertions.assertEquals(Arrays.asList("litalias1", "litalias2"), literal.getMinor());
+        Assertions.assertEquals(ArgumentMode.LITERAL, literal.getArgumentMode());
+
+        final SyntaxFragment requirement = fragments.get(1);
+        Assertions.assertEquals("requirement", requirement.getMajor());
+        Assertions.assertEquals(Collections.emptyList(), requirement.getMinor());
+        Assertions.assertEquals(ArgumentMode.REQUIRED, requirement.getArgumentMode());
+
+        final SyntaxFragment optional = fragments.get(2);
+        Assertions.assertEquals("optional", optional.getMajor());
+        Assertions.assertEquals(Collections.emptyList(), optional.getMinor());
+        Assertions.assertEquals(ArgumentMode.OPTIONAL, optional.getArgumentMode());
+    }
+
+    @Test
+    void testParse() {
+        List<SyntaxFragment> fragments = new SyntaxParser().apply(
+                "literal <requirement> [optional]");
+
+        Assertions.assertEquals(3, fragments.size());
+
+        final SyntaxFragment literal = fragments.get(0);
+        Assertions.assertEquals("literal", literal.getMajor());
+        Assertions.assertEquals(Collections.emptyList(), literal.getMinor());
+        Assertions.assertEquals(ArgumentMode.LITERAL, literal.getArgumentMode());
+
+        final SyntaxFragment requirement = fragments.get(1);
+        Assertions.assertEquals("requirement", requirement.getMajor());
+        Assertions.assertEquals(Collections.emptyList(), requirement.getMinor());
+        Assertions.assertEquals(ArgumentMode.REQUIRED, requirement.getArgumentMode());
+
+        final SyntaxFragment optional = fragments.get(2);
+        Assertions.assertEquals("optional", optional.getMajor());
+        Assertions.assertEquals(Collections.emptyList(), optional.getMinor());
+        Assertions.assertEquals(ArgumentMode.OPTIONAL, optional.getArgumentMode());
+    }
+
+    @Test
+    void testParseSpecialCharacters() {
+        List<SyntaxFragment> fragments = new SyntaxParser().apply(
+                "l_itera-l|with_ali-as <r_equiremen-t> [o_ptiona-l]");
+
+        Assertions.assertEquals(3, fragments.size());
+
+        final SyntaxFragment literal = fragments.get(0);
+        Assertions.assertEquals("l_itera-l", literal.getMajor());
+        Assertions.assertEquals(Collections.singletonList("with_ali-as"), literal.getMinor());
+        Assertions.assertEquals(ArgumentMode.LITERAL, literal.getArgumentMode());
+
+        final SyntaxFragment requirement = fragments.get(1);
+        Assertions.assertEquals("r_equiremen-t", requirement.getMajor());
+        Assertions.assertEquals(Collections.emptyList(), requirement.getMinor());
+        Assertions.assertEquals(ArgumentMode.REQUIRED, requirement.getArgumentMode());
+
+        final SyntaxFragment optional = fragments.get(2);
+        Assertions.assertEquals("o_ptiona-l", optional.getMajor());
+        Assertions.assertEquals(Collections.emptyList(), optional.getMinor());
+        Assertions.assertEquals(ArgumentMode.OPTIONAL, optional.getArgumentMode());
+    }
+}