diff --git a/ZString.cpp b/ZString.cpp
index e7034ab..cb0fc9e 100644
--- a/ZString.cpp
+++ b/ZString.cpp
@@ -373,6 +373,8 @@ namespace coreutils {
    }
 
    bool ZString::startsWithNumber() {
+      if(*cursor == '-')
+	return true;
       return ((*cursor >= '0') && (*cursor <= '9'));
    }