diff --git a/lldb/include/lldb/Core/Debugger.h b/lldb/include/lldb/Core/Debugger.h
index cdba0d6da6b9..f1b943263537 100644
--- a/lldb/include/lldb/Core/Debugger.h
+++ b/lldb/include/lldb/Core/Debugger.h
@@ -88,7 +88,9 @@ public:
     void
     SetTerminalWidth (uint32_t term_width)
     {
-        m_term_width = term_width;
+        Error err;
+        if (ValidTermWidthValue(term_width, err))
+            m_term_width = term_width;
     }
 
     uint32_t
@@ -229,6 +231,9 @@ protected:
     bool
     ValidTermWidthValue (const char *value, Error err);
 
+    bool
+    ValidTermWidthValue (uint32_t value, Error err);
+
     const ConstString
     CreateInstanceName ();
 
diff --git a/lldb/source/Core/Debugger.cpp b/lldb/source/Core/Debugger.cpp
index 6bb68db42f1c..9a7a3f576201 100644
--- a/lldb/source/Core/Debugger.cpp
+++ b/lldb/source/Core/Debugger.cpp
@@ -2523,10 +2523,7 @@ DebuggerInstanceSettings::ValidTermWidthValue (const char *value, Error err)
         
         if (end && end[0] == '\0')
         {
-            if (width >= 10 && width <= 1024)
-                valid = true;
-            else
-                err.SetErrorString ("invalid term-width value; value must be between 10 and 1024");
+            return ValidTermWidthValue (width, err);
         }
         else
             err.SetErrorStringWithFormat ("'%s' is not a valid unsigned integer string", value);
@@ -2535,6 +2532,17 @@ DebuggerInstanceSettings::ValidTermWidthValue (const char *value, Error err)
     return valid;
 }
 
+bool
+DebuggerInstanceSettings::ValidTermWidthValue (uint32_t value, Error err)
+{
+    if (value >= 10 && value <= 1024)
+        return true;
+    else
+    {
+        err.SetErrorString ("invalid term-width value; value must be between 10 and 1024");
+        return false;
+    }
+}
 
 void
 DebuggerInstanceSettings::UpdateInstanceSettingsVariable (const ConstString &var_name,
diff --git a/lldb/tools/driver/Driver.cpp b/lldb/tools/driver/Driver.cpp
index 63844af8afd3..b022f38b7108 100644
--- a/lldb/tools/driver/Driver.cpp
+++ b/lldb/tools/driver/Driver.cpp
@@ -1484,11 +1484,9 @@ sigwinch_handler (int signo)
     if (isatty (STDIN_FILENO)
         && ::ioctl (STDIN_FILENO, TIOCGWINSZ, &window_size) == 0)
     {
-        if ((window_size.ws_col > 0) && (strlen (g_debugger_name) > 0))
+        if ((window_size.ws_col > 0) && g_driver != NULL)
         {
-            char width_str_buffer[25];
-            ::sprintf (width_str_buffer, "%d", window_size.ws_col);
-            SBDebugger::SetInternalVariable ("term-width", width_str_buffer, g_debugger_name);
+            g_driver->GetDebugger().SetTerminalWidth (window_size.ws_col);
         }
     }
 }