diff --git a/src/tools/disco/Character.hpp b/src/tools/disco/Character.hpp
index 7360326..2d9236d 100644
--- a/src/tools/disco/Character.hpp
+++ b/src/tools/disco/Character.hpp
@@ -38,9 +38,13 @@ class Character : public BaseFixedWidthField< Width > {
    *  @param[in,out] iter       an iterator to a character in a range
    */
   template < typename Representation, typename Iterator >
-  static Representation read( Iterator& iter, const Iterator& ) {
+  static Representation read( Iterator& iter, const Iterator& end ) {
 
     Representation value;
+    if ( iter >= end ) {
+
+      return value;
+    }
     value.reserve( Width );
 
     unsigned int position = 0;
diff --git a/src/tools/disco/Column.hpp b/src/tools/disco/Column.hpp
index 6f7310e..255e081 100644
--- a/src/tools/disco/Column.hpp
+++ b/src/tools/disco/Column.hpp
@@ -37,10 +37,10 @@ class Column : public BaseFixedWidthField< Width > {
    *  @param[in,out] iter   an iterator to a character in a range
    */
   template < typename Iterator >
-  static void read( Iterator& iter, const Iterator& ) {
+  static void read( Iterator& iter, const Iterator& end ) {
 
     unsigned int position = 0;
-    while( position < Width && ! ( isNewLine( iter ) || isEndOfFile( iter ) ) ) {
+    while( position < Width && ! ( isNewLine( iter ) || isEndOfFile( iter ) || iter >= end ) ) {
 
       ++position;
       ++iter;
diff --git a/src/tools/disco/Integer.hpp b/src/tools/disco/Integer.hpp
index cdef43b..6d2333d 100644
--- a/src/tools/disco/Integer.hpp
+++ b/src/tools/disco/Integer.hpp
@@ -41,14 +41,14 @@ class Integer : public BaseFixedWidthField< Width > {
    *  @param[in,out] iter       an iterator to a character in a range
    */
   template < typename Representation, typename Iterator >
-  static Representation read( Iterator& iter, const Iterator& ) {
+  static Representation read( Iterator& iter, const Iterator& end ) {
 
     unsigned int position = 0;
-    const auto end = iter + Width;
+    const auto final = iter + Width;
     Representation value = 0;
 
     skipSpaces( iter, position );
-    if ( isNewLine( iter ) || isEndOfFile( iter ) || Width == position ) {
+    if ( isNewLine( iter ) || isEndOfFile( iter ) || Width == position || iter >= end ) {
 
       return value;
     }
@@ -62,7 +62,7 @@ class Integer : public BaseFixedWidthField< Width > {
     // we are using fast_float::from_chars instead of std::from_chars since
     // not all standard c++ libraries implement the floating point version of
     // std::from_chars
-    auto result = fast_float::from_chars( &*iter, &*end, value );
+    auto result = fast_float::from_chars( &*iter, &*final, value );
     if ( result.ec == std::errc() ) {
 
       auto advance = result.ptr - &*iter;
diff --git a/src/tools/disco/Real.hpp b/src/tools/disco/Real.hpp
index 107f19b..f28ee53 100644
--- a/src/tools/disco/Real.hpp
+++ b/src/tools/disco/Real.hpp
@@ -33,14 +33,14 @@ class Real : public BaseFixedWidthField< Width > {
    *  @param[in,out] iter       an iterator to a character in a range
    */
   template < typename Representation, typename Iterator >
-  static Representation read( Iterator& iter, const Iterator& ) {
+  static Representation read( Iterator& iter, const Iterator& end ) {
 
     unsigned int position = 0;
-    const auto end = iter + Width;
+    const auto final = iter + Width;
     Representation value = 0.0;
 
     skipSpaces( iter, position );
-    if ( isNewLine( iter ) || isEndOfFile( iter ) || Width == position ) {
+    if ( isNewLine( iter ) || isEndOfFile( iter ) || Width == position || iter >= end ) {
 
       return value;
     }
@@ -56,7 +56,7 @@ class Real : public BaseFixedWidthField< Width > {
     // of std::from_chars and because this allows us to read fortran formatted
     // floats
     fast_float::parse_options options{ fast_float::chars_format::fortran };
-    auto result = fast_float::from_chars_advanced( &*iter, &*end, value, options );
+    auto result = fast_float::from_chars_advanced( &*iter, &*final, value, options );
     if ( result.ec == std::errc() ) {
 
       auto advance = result.ptr - &*iter;