diff --git a/LEGO1/mxatomid.h b/LEGO1/mxatomid.h
index 5d4cd10f..3abe6479 100644
--- a/LEGO1/mxatomid.h
+++ b/LEGO1/mxatomid.h
@@ -20,6 +20,7 @@ class MxAtomId {
 	MxAtomId() { this->m_internal = 0; }
 
 	inline MxBool operator==(const MxAtomId& p_atomId) const { return this->m_internal == p_atomId.m_internal; }
+	inline MxBool operator!=(const MxAtomId& p_atomId) const { return this->m_internal != p_atomId.m_internal; }
 
 	void Clear();