diff --git a/sbe-tool/src/main/java/uk/co/real_logic/sbe/xml/SetType.java b/sbe-tool/src/main/java/uk/co/real_logic/sbe/xml/SetType.java
index 467ac93b80..56ce301fe8 100644
--- a/sbe-tool/src/main/java/uk/co/real_logic/sbe/xml/SetType.java
+++ b/sbe-tool/src/main/java/uk/co/real_logic/sbe/xml/SetType.java
@@ -223,7 +223,7 @@ public Choice(final Node node, final PrimitiveType encodingType)
             deprecated = Integer.parseInt(getAttributeValue(node, "deprecated", "0"));
 
             // choice values are bit positions (0, 1, 2, 3, 4, etc.) from LSB to MSB
-            if (value.longValue() >= (encodingType.size() * 8L))
+            if (value.longValue() < 0 || value.longValue() >= (encodingType.size() * 8L))
             {
                 throw new IllegalArgumentException("Choice value out of bounds: " + value.longValue());
             }
diff --git a/sbe-tool/src/test/java/uk/co/real_logic/sbe/xml/SetTypeTest.java b/sbe-tool/src/test/java/uk/co/real_logic/sbe/xml/SetTypeTest.java
index 60d09daa15..fcaf2a020b 100644
--- a/sbe-tool/src/test/java/uk/co/real_logic/sbe/xml/SetTypeTest.java
+++ b/sbe-tool/src/test/java/uk/co/real_logic/sbe/xml/SetTypeTest.java
@@ -175,6 +175,21 @@ void shouldThrowExceptionWhenValueOutOfBoundsSpecified()
             parseTestXmlWithMap("/types/set", testXmlString));
     }
 
+    @Test
+    void shouldThrowExceptionWhenNegativeValueSpecified()
+    {
+        final String testXmlString =
+            "<types>" +
+            "<set name=\"biOp\" encodingType=\"uint8\">" +
+            "    <choice name=\"Bit0\">0</choice>" +
+            "    <choice name=\"BitNeg\">-1</choice>" +
+            "</set>" +
+            "</types>";
+
+        assertThrows(IllegalArgumentException.class, () ->
+            parseTestXmlWithMap("/types/set", testXmlString));
+    }
+
     @Test
     void shouldHandleEncodingTypesWithNamedTypes() throws Exception
     {