diff --git a/libinterp/corefcn/gripes.cc b/libinterp/corefcn/gripes.cc
--- a/libinterp/corefcn/gripes.cc
+++ b/libinterp/corefcn/gripes.cc
@@ -132,6 +132,21 @@ gripe_data_conversion (const char *from,
 }
 
 void
+gripe_wrong_type_arg (const char *s, bool is_error)
+{
+  if (is_error)
+    error ("wrong type argument '%s'", s);
+  else
+    warning ("wrong type argument '%s'", s);
+}
+
+void
+gripe_wrong_type_arg (const std::string& s, bool is_error)
+{
+  gripe_wrong_type_arg (s.c_str (), is_error);
+}
+
+void
 gripe_wrong_type_arg (const char *name, const char *s, bool is_error)
 {
   if (is_error)
diff --git a/libinterp/corefcn/gripes.h b/libinterp/corefcn/gripes.h
--- a/libinterp/corefcn/gripes.h
+++ b/libinterp/corefcn/gripes.h
@@ -79,6 +79,12 @@ extern OCTINTERP_API void
 gripe_data_conversion (const char *from, const char *to);
 
 extern OCTINTERP_API void
+gripe_wrong_type_arg (const char *s, bool is_error = true);
+
+extern OCTINTERP_API void
+gripe_wrong_type_arg (const std::string& s, bool is_error = true);
+
+extern OCTINTERP_API void
 gripe_wrong_type_arg (const char *name, const char *s,
                       bool is_error = true);
 
diff --git a/libinterp/octave-value/ov-base.cc b/libinterp/octave-value/ov-base.cc
--- a/libinterp/octave-value/ov-base.cc
+++ b/libinterp/octave-value/ov-base.cc
@@ -913,6 +913,17 @@ octave_base_value::string_value (bool fo
   return retval;
 }
 
+std::string
+octave_base_value::string_value (const std::string& msg) const
+{
+  if (msg.empty ())
+    gripe_wrong_type_arg (type_name ());
+  else
+    error ("%s", msg.c_str ());
+
+  return std::string ();
+}
+
 Array<std::string>
 octave_base_value::cellstr_value (void) const
 {
diff --git a/libinterp/octave-value/ov-base.h b/libinterp/octave-value/ov-base.h
--- a/libinterp/octave-value/ov-base.h
+++ b/libinterp/octave-value/ov-base.h
@@ -564,6 +564,8 @@ public:
 
   virtual std::string string_value (bool force = false) const;
 
+  virtual std::string string_value (const std::string& msg) const;
+
   virtual Array<std::string> cellstr_value (void) const;
 
   virtual Range range_value (void) const;
diff --git a/libinterp/octave-value/ov-str-mat.cc b/libinterp/octave-value/ov-str-mat.cc
--- a/libinterp/octave-value/ov-str-mat.cc
+++ b/libinterp/octave-value/ov-str-mat.cc
@@ -258,6 +258,40 @@ octave_char_matrix_str::string_value (bo
   return retval;
 }
 
+std::string
+octave_char_matrix_str::string_value (const std::string& msg) const
+{
+  std::string retval;
+
+  if (msg.empty ())
+    return string_value ();
+  else
+    {
+      bool conversion_error = false;
+
+      if (matrix.ndims () == 2)
+        {
+          charMatrix chm (matrix);
+
+          try
+            {
+              retval = chm.row_as_string (0);  // FIXME?
+            }
+          catch (const octave_execution_exception&)
+            {
+              conversion_error = true;
+            }
+        }
+      else
+        conversion_error = true;
+
+      if (conversion_error)
+        error ("%s", msg.c_str ());
+    }
+
+  return retval;
+}
+
 Array<std::string>
 octave_char_matrix_str::cellstr_value (void) const
 {
diff --git a/libinterp/octave-value/ov-str-mat.h b/libinterp/octave-value/ov-str-mat.h
--- a/libinterp/octave-value/ov-str-mat.h
+++ b/libinterp/octave-value/ov-str-mat.h
@@ -129,6 +129,8 @@ public:
 
   std::string string_value (bool force = false) const;
 
+  std::string string_value (const std::string& msg) const;
+
   Array<std::string> cellstr_value (void) const;
 
   octave_value sort (octave_idx_type dim = 0, sortmode mode = ASCENDING) const
diff --git a/libinterp/octave-value/ov.h b/libinterp/octave-value/ov.h
--- a/libinterp/octave-value/ov.h
+++ b/libinterp/octave-value/ov.h
@@ -897,6 +897,12 @@ public:
   std::string string_value (bool force = false) const
   { return rep->string_value (force); }
 
+  std::string string_value (const char *msg) const
+  { return string_value (std::string (msg ? msg : "")); }
+
+  std::string string_value (const std::string& msg) const
+  { return rep->string_value (msg); }
+
   Array<std::string> cellstr_value (void) const
   { return rep->cellstr_value (); }