diff --git a/SystemTools.cxx b/SystemTools.cxx
index 652649f4af0a753869fbea0d3f5d5cfa18ab1b1a..7891708655a160faf0015b3ee6b6c5b7036ae369 100644
--- a/SystemTools.cxx
+++ b/SystemTools.cxx
@@ -3085,7 +3085,7 @@ SystemToolsAppendComponents(
     {
     if(*i == "..")
       {
-      if(out_components.begin() != out_components.end())
+      if(out_components.size() > 1)
         {
         out_components.erase(out_components.end()-1, out_components.end());
         }