diff --git a/ChangeLog b/ChangeLog
index b8c23e91..775b6b45 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -15826,3 +15826,5 @@
 	* Added a 'Air Gate' ['AG'] RML.
 2017-06-08 Fred Gleason <fredg@paravelsystems.com>
 	* Added 'scripts/engine_conv.py'.
+2017-06-13 Fred Gleason <fredg@paravelsystems.com>
+	* Applied fix for RDValidator from Robert Chipperfield.
diff --git a/lib/rdtextvalidator.cpp b/lib/rdtextvalidator.cpp
index 475a3591..22fe4e24 100644
--- a/lib/rdtextvalidator.cpp
+++ b/lib/rdtextvalidator.cpp
@@ -34,7 +34,11 @@ RDTextValidator::RDTextValidator(QObject *parent,const char *name,bool allow_quo
 
 QValidator::State RDTextValidator::validate(QString &input,int &pos) const
 {
-  char c=input.at(pos-1).latin1();
+  if(input.length()==0) {
+    return QValidator::Acceptable;
+  }
+  int inspection_pos=std::max(0,std::min((int)input.length()-1,pos));
+  char c=input.at(inspection_pos).latin1();
   for(unsigned i=0;i<banned_chars.size();i++) {
     if(banned_chars[i]==c) {
       return QValidator::Invalid;