diff --git a/gtk/gtkbuilder.c b/gtk/gtkbuilder.c
index 06ab4107ee..7ed026c0a7 100644
--- a/gtk/gtkbuilder.c
+++ b/gtk/gtkbuilder.c
@@ -239,7 +239,7 @@
 
 #include "config.h"
 #include <errno.h> /* errno */
-#include <stdlib.h> /* strtol, strtoul */
+#include <stdlib.h>
 #include <string.h> /* strlen */
 
 #include "gtkbuilder.h"
@@ -1451,9 +1451,9 @@ gtk_builder_value_from_string_type (GtkBuilder   *builder,
     case G_TYPE_LONG:
       {
         long l;
-        gchar *endptr;
+        gchar *endptr = NULL;
         errno = 0;
-        l = strtol (string, &endptr, 0);
+        l = g_ascii_strtoll (string, &endptr, 0);
         if (errno || endptr == string)
           {
 	    g_set_error (error,
@@ -1474,9 +1474,9 @@ gtk_builder_value_from_string_type (GtkBuilder   *builder,
     case G_TYPE_ULONG:
       {
         gulong ul;
-        gchar *endptr;
+        gchar *endptr = NULL;
         errno = 0;
-        ul = strtoul (string, &endptr, 0);
+        ul = g_ascii_strtoull (string, &endptr, 0);
         if (errno || endptr == string)
           {
 	    g_set_error (error,
@@ -1520,7 +1520,7 @@ gtk_builder_value_from_string_type (GtkBuilder   *builder,
     case G_TYPE_DOUBLE:
       {
         gdouble d;
-        gchar *endptr;
+        gchar *endptr = NULL;
         errno = 0;
         d = g_ascii_strtod (string, &endptr);
         if (errno || endptr == string)
@@ -1676,8 +1676,10 @@ _gtk_builder_enum_from_string (GType         type,
   
   ret = TRUE;
 
-  value = strtoul (string, &endptr, 0);
-  if (endptr != string) /* parsed a number */
+  endptr = NULL;
+  errno = 0;
+  value = g_ascii_strtoull (string, &endptr, 0);
+  if (errno == 0 && endptr != string) /* parsed a number */
     *enum_value = value;
   else
     {
@@ -1723,9 +1725,11 @@ _gtk_builder_flags_from_string (GType         type,
   g_return_val_if_fail (string != 0, FALSE);
 
   ret = TRUE;
-  
-  value = strtoul (string, &endptr, 0);
-  if (endptr != string) /* parsed a number */
+
+  endptr = NULL;
+  errno = 0;
+  value = g_ascii_strtoull (string, &endptr, 0);
+  if (errno == 0 && endptr != string) /* parsed a number */
     *flags_value = value;
   else
     {
diff --git a/gtk/gtkcelllayout.c b/gtk/gtkcelllayout.c
index 86e8e39644..8388b5f7d5 100644
--- a/gtk/gtkcelllayout.c
+++ b/gtk/gtkcelllayout.c
@@ -335,9 +335,9 @@ attributes_text_element (GMarkupParseContext *context,
   if (!parser_data->attr_name)
     return;
 
-  errno = 0;
   string = g_strndup (text, text_len);
-  l = strtol (string, &endptr, 0);
+  errno = 0;
+  l = g_ascii_strtoll (string, &endptr, 0);
   if (errno || endptr == string)
     {
       g_set_error (error, 
diff --git a/gtk/gtkdialog.c b/gtk/gtkdialog.c
index 86e28e320d..cf9592710a 100644
--- a/gtk/gtkdialog.c
+++ b/gtk/gtkdialog.c
@@ -1357,7 +1357,7 @@ gtk_dialog_buildable_custom_finished (GtkBuildable *buildable,
 	}
 
       ad = get_response_data (GTK_WIDGET (object), TRUE);
-      ad->response_id = atoi (item->response_id);
+      ad->response_id = g_ascii_strtoll (item->response_id, NULL, 10);
 
       if (GTK_IS_BUTTON (object))
 	signal_id = g_signal_lookup ("clicked", GTK_TYPE_BUTTON);
diff --git a/gtk/gtktextbufferserialize.c b/gtk/gtktextbufferserialize.c
index 04f684bd4f..16a36d3994 100644
--- a/gtk/gtktextbufferserialize.c
+++ b/gtk/gtktextbufferserialize.c
@@ -28,6 +28,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <errno.h>
 
 #include "gdk-pixbuf/gdk-pixdata.h"
 #include "gtktextbufferserialize.h"
@@ -113,9 +114,10 @@ deserialize_value (const gchar *str,
       gchar *tmp;
       int v;
 
-      v = strtol (str, &tmp, 10);
+      errno = 0;
+      v = g_ascii_strtoll (str, &tmp, 10);
 
-      if (tmp == NULL || tmp == str)
+      if (errno || tmp == NULL || tmp == str)
 	return FALSE;
 
       g_value_set_int (value, v);
@@ -143,26 +145,32 @@ deserialize_value (const gchar *str,
       gchar *tmp;
 
       old = str;
-      color.red = strtol (old, &tmp, 16);
+      tmp = NULL;
+      errno = 0;
+      color.red = g_ascii_strtoll (old, &tmp, 16);
 
-      if (tmp == NULL || tmp == old)
+      if (errno || tmp == old)
 	return FALSE;
 
       old = tmp;
       if (*old++ != ':')
 	return FALSE;
 
-      color.green = strtol (old, &tmp, 16);
-      if (tmp == NULL || tmp == old)
+      tmp = NULL;
+      errno = 0;
+      color.green = g_ascii_strtoll (old, &tmp, 16);
+      if (errno || tmp == old)
 	return FALSE;
 
       old = tmp;
       if (*old++ != ':')
 	return FALSE;
 
-      color.blue = strtol (old, &tmp, 16);
+      tmp = NULL;
+      errno = 0;
+      color.blue = g_ascii_strtoll (old, &tmp, 16);
 
-      if (tmp == NULL || tmp == old || *tmp != '\0')
+      if (errno || tmp == old || *tmp != '\0')
 	return FALSE;
 
       g_value_set_boxed (value, &color);
@@ -836,9 +844,11 @@ check_id_or_name (GMarkupParseContext  *context,
 	  has_id = TRUE;
 
 	  /* Try parsing the integer */
-	  *id = strtol (attribute_values[i], &tmp, 10);
+          tmp = NULL;
+          errno = 0;
+	  *id = g_ascii_strtoll (attribute_values[i], &tmp, 10);
 
-	  if (tmp == NULL || tmp == attribute_values[i])
+	  if (errno || tmp == attribute_values[i])
 	    {
 	      set_error (error, context,
 			 G_MARKUP_ERROR, G_MARKUP_ERROR_PARSE,
@@ -1291,9 +1301,11 @@ parse_tag_element (GMarkupParseContext  *context,
 	    }
 	}
 
-      prio = strtol (priority, &tmp, 10);
+      tmp = NULL;
+      errno = 0;
+      prio = g_ascii_strtoll (priority, &tmp, 10);
 
-      if (tmp == NULL || tmp == priority)
+      if (errno || tmp == priority)
 	{
 	  set_error (error, context,
 		     G_MARKUP_ERROR, G_MARKUP_ERROR_PARSE,
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index fb63d1c4d2..216054cbcd 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -531,9 +531,10 @@ extract_time_from_startup_id (const gchar* startup_id)
       /* Skip past the "_TIME" part */
       timestr += 5;
 
+      end = NULL;
       errno = 0;
-      timestamp = strtoul (timestr, &end, 0);
-      if (end != timestr && errno == 0)
+      timestamp = g_ascii_strtoull (timestr, &end, 0);
+      if (errno == 0 && end != timestr)
         retval = timestamp;
     }