diff --git a/dlls/nodes.h b/dlls/nodes.h
index cb19aeb844..becfd07bc8 100644
--- a/dlls/nodes.h
+++ b/dlls/nodes.h
@@ -216,7 +216,7 @@ class CGraph
 	inline	CNode &Node( int i )
 	{
 #if _DEBUG
-		if ( !m_pNodes || i < 0 || i > m_cNodes )
+		if ( !m_pNodes || i < 0 || i >= m_cNodes )
 			ALERT( at_error, "Bad Node!\n" );
 #endif
 		return m_pNodes[i];
@@ -225,7 +225,7 @@ class CGraph
 	inline	CLink &Link( int i )
 	{
 #if _DEBUG
-		if ( !m_pLinkPool || i < 0 || i > m_cLinks )
+		if ( !m_pLinkPool || i < 0 || i >= m_cLinks )
 			ALERT( at_error, "Bad link!\n" );
 #endif
 		return m_pLinkPool[i];