diff --git a/glib/gbase64.c b/glib/gbase64.c
index 043593b05..2ea4a4ef4 100644
--- a/glib/gbase64.c
+++ b/glib/gbase64.c
@@ -424,7 +424,8 @@ guchar *
 g_base64_decode_inplace (gchar *text,
                          gsize *out_len)
 {
-  gint input_length, state = 0;
+  gint state = 0;
+  size_t input_length;
   guint save = 0;
 
   g_return_val_if_fail (text != NULL, NULL);
diff --git a/glib/gdate.c b/glib/gdate.c
index c509bd303..c0d486c9d 100644
--- a/glib/gdate.c
+++ b/glib/gdate.c
@@ -2258,6 +2258,7 @@ win32_strftime_helper (const GDate     *d,
   gchar *convbuf;
   glong convlen = 0;
   gsize retval;
+  size_t format_len = strlen (format);
 
   systemtime.wYear = tm->tm_year + 1900;
   systemtime.wMonth = tm->tm_mon + 1;
@@ -2269,7 +2270,8 @@ win32_strftime_helper (const GDate     *d,
   systemtime.wMilliseconds = 0;
   
   lcid = GetThreadLocale ();
-  result = g_array_sized_new (FALSE, FALSE, sizeof (wchar_t), MAX (128, strlen (format) * 2));
+  result = g_array_sized_new (FALSE, FALSE, sizeof (wchar_t),
+                              (format_len <= 64) ? (guint) format_len * 2 : 128);
 
   p = format;
   while (*p)
diff --git a/glib/gdatetime.c b/glib/gdatetime.c
index b5372d834..702a77c51 100644
--- a/glib/gdatetime.c
+++ b/glib/gdatetime.c
@@ -3268,7 +3268,7 @@ g_date_time_format_utf8 (GDateTime   *datetime,
 			 GString     *outstr,
 			 gboolean     locale_is_utf8)
 {
-  guint     len;
+  size_t len;
   guint     colons;
   gunichar  c;
   gboolean  alt_digits = FALSE;
diff --git a/glib/genviron.c b/glib/genviron.c
index b72871b95..2b0136006 100644
--- a/glib/genviron.c
+++ b/glib/genviron.c
@@ -647,7 +647,7 @@ g_get_environ (void)
 {
   gunichar2 *strings;
   gchar **result;
-  gint i, n;
+  size_t i, n;
 
   strings = GetEnvironmentStringsW ();
   for (n = 0, i = 0; strings[n]; i++)
diff --git a/glib/gfileutils.c b/glib/gfileutils.c
index 2801777e4..f40400ca5 100644
--- a/glib/gfileutils.c
+++ b/glib/gfileutils.c
@@ -373,7 +373,7 @@ g_file_test (const gchar *filename,
     {
       const gchar *lastdot = strrchr (filename, '.');
       const gchar *pathext = NULL, *p;
-      int extlen;
+      size_t extlen;
 
       if (lastdot == NULL)
         break;
@@ -401,7 +401,7 @@ g_file_test (const gchar *filename,
 	  const gchar *q = strchr (p, ';');
 	  if (q == NULL)
 	    q = p + strlen (p);
-	  if (extlen == q - p &&
+	  if (extlen == (size_t) (q - p) &&
 	      memcmp (lastdot, p, extlen) == 0)
 	    {
 	      g_free ((gchar *) pathext);
diff --git a/glib/gmessages.c b/glib/gmessages.c
index f325a9196..2ce651a71 100644
--- a/glib/gmessages.c
+++ b/glib/gmessages.c
@@ -1420,9 +1420,9 @@ win32_is_pipe_tty (int fd)
   gboolean result = FALSE;
   HANDLE h_fd;
   FILE_NAME_INFO *info = NULL;
-  gint info_size = sizeof (FILE_NAME_INFO) + sizeof (WCHAR) * MAX_PATH;
+  size_t info_size = sizeof (FILE_NAME_INFO) + sizeof (WCHAR) * MAX_PATH;
   wchar_t *name = NULL;
-  gint length;
+  size_t length;
 
   h_fd = (HANDLE) _get_osfhandle (fd);
 
diff --git a/glib/goption.c b/glib/goption.c
index 530e0cdba..785b151f0 100644
--- a/glib/goption.c
+++ b/glib/goption.c
@@ -1461,7 +1461,7 @@ parse_long_option (GOptionContext *context,
         }
       else
         {
-          gint len = strlen (group->entries[j].long_name);
+          size_t len = strlen (group->entries[j].long_name);
 
           if (strncmp (arg, group->entries[j].long_name, len) == 0 &&
               (arg[len] == '=' || arg[len] == 0))
diff --git a/glib/gpattern.c b/glib/gpattern.c
index bf61da36f..f77e69b6b 100644
--- a/glib/gpattern.c
+++ b/glib/gpattern.c
@@ -65,9 +65,9 @@ typedef enum
 struct _GPatternSpec
 {
   GMatchType match_type;
-  guint      pattern_length;
-  guint      min_length;
-  guint      max_length;
+  size_t     pattern_length;
+  size_t     min_length;
+  size_t     max_length;
   gchar     *pattern;
 };
 
diff --git a/glib/gstrfuncs.c b/glib/gstrfuncs.c
index 9af21a953..3688bea49 100644
--- a/glib/gstrfuncs.c
+++ b/glib/gstrfuncs.c
@@ -930,7 +930,7 @@ g_ascii_formatd (gchar       *buffer,
   const char *decimal_point;
   gsize decimal_point_len;
   gchar *p;
-  int rest_len;
+  size_t rest_len;
   gchar format_char;
 
   g_return_val_if_fail (buffer != NULL, NULL);
diff --git a/glib/gstring.c b/glib/gstring.c
index 463bfeccc..bdd068344 100644
--- a/glib/gstring.c
+++ b/glib/gstring.c
@@ -134,7 +134,7 @@ g_string_new (const gchar *init)
     string = g_string_sized_new (2);
   else
     {
-      gint len;
+      size_t len;
 
       len = strlen (init);
       string = g_string_sized_new (len + 2);
diff --git a/glib/gtestutils.c b/glib/gtestutils.c
index 5c5f9051f..253cfa7b3 100644
--- a/glib/gtestutils.c
+++ b/glib/gtestutils.c
@@ -3035,7 +3035,7 @@ static gboolean
 path_has_prefix (const char *path,
                  const char *prefix)
 {
-  int prefix_len = strlen (prefix);
+  size_t prefix_len = strlen (prefix);
 
   return (strncmp (path, prefix, prefix_len) == 0 &&
           (path[prefix_len] == '\0' ||
diff --git a/glib/gtranslit.c b/glib/gtranslit.c
index c264241cc..85ffb1326 100644
--- a/glib/gtranslit.c
+++ b/glib/gtranslit.c
@@ -187,11 +187,11 @@ lookup_item_id_for_locale (const gchar *locale)
 {
   gchar key[MAX_LOCALE_NAME + 1];
   const gchar *language;
-  guint language_len;
+  size_t language_len;
   const gchar *territory = NULL;
-  guint territory_len = 0;
+  size_t territory_len = 0;
   const gchar *modifier = NULL;
-  guint modifier_len = 0;
+  size_t modifier_len = 0;
   const gchar *next_char;
   guint id;
 
diff --git a/glib/guniprop.c b/glib/guniprop.c
index 61acad6e6..e147829e2 100644
--- a/glib/guniprop.c
+++ b/glib/guniprop.c
@@ -805,7 +805,7 @@ output_special_case (gchar *out_buffer,
 		     int    which)
 {
   const gchar *p = special_case_table + offset;
-  gint len;
+  size_t len;
 
   if (type != G_UNICODE_TITLECASE_LETTER)
     p = g_utf8_next_char (p);
diff --git a/glib/gutf8.c b/glib/gutf8.c
index 5a875ce26..dd9966df5 100644
--- a/glib/gutf8.c
+++ b/glib/gutf8.c
@@ -1250,7 +1250,7 @@ g_utf16_to_ucs4 (const gunichar2  *str,
   const gunichar2 *in;
   gchar *out;
   gchar *result = NULL;
-  gint n_bytes;
+  size_t n_bytes;
   gunichar high_surrogate;
 
   g_return_val_if_fail (str != NULL, NULL);
diff --git a/glib/gutils.c b/glib/gutils.c
index 5eaa63845..057e2bcd7 100644
--- a/glib/gutils.c
+++ b/glib/gutils.c
@@ -196,7 +196,7 @@ g_find_program_in_path (const gchar *program)
       strchr (last_dot, '\\') != NULL ||
       strchr (last_dot, '/') != NULL)
     {
-      const gint program_length = strlen (program);
+      const size_t program_length = strlen (program);
       gchar *pathext = g_build_path (";",
 				     ".exe;.cmd;.bat;.com",
 				     g_getenv ("PATHEXT"),
diff --git a/glib/gvariant-parser.c b/glib/gvariant-parser.c
index 243a34f57..8bd16766c 100644
--- a/glib/gvariant-parser.c
+++ b/glib/gvariant-parser.c
@@ -327,10 +327,10 @@ static gboolean
 token_stream_peek_string (TokenStream *stream,
                           const gchar *token)
 {
-  gint length = strlen (token);
+  size_t length = strlen (token);
 
   return token_stream_prepare (stream) &&
-         stream->stream - stream->this == length &&
+         (size_t) (stream->stream - stream->this) == length &&
          memcmp (stream->this, token, length) == 0;
 }
 
diff --git a/glib/tests/array-test.c b/glib/tests/array-test.c
index 70f56e8a1..df9d15bdc 100644
--- a/glib/tests/array-test.c
+++ b/glib/tests/array-test.c
@@ -133,7 +133,7 @@ array_new_zero_terminated (void)
   garray = g_array_new (TRUE, FALSE, sizeof (gchar));
   g_assert_cmpuint (garray->len, ==, 0);
 
-  g_array_append_vals (garray, "hello", strlen ("hello"));
+  g_array_append_vals (garray, "hello", (guint) strlen ("hello"));
   g_assert_cmpuint (garray->len, ==, 5);
   g_assert_cmpstr (garray->data, ==, "hello");
 
diff --git a/glib/tests/gvariant.c b/glib/tests/gvariant.c
index c24cd2f3e..27586be71 100644
--- a/glib/tests/gvariant.c
+++ b/glib/tests/gvariant.c
@@ -313,7 +313,7 @@ invalid_mutation (const gchar *type_string)
 
   /* else, perform a random mutation at a random point */
   {
-    gint length, n;
+    size_t length, n;
     gchar *new;
     gchar p;
 
diff --git a/glib/tests/pattern.c b/glib/tests/pattern.c
index b590acb8a..414b86358 100644
--- a/glib/tests/pattern.c
+++ b/glib/tests/pattern.c
@@ -37,9 +37,9 @@ typedef enum
 struct _GPatternSpec
 {
   GMatchType match_type;
-  guint      pattern_length;
-  guint      min_length;
-  guint      max_length;
+  size_t     pattern_length;
+  size_t     min_length;
+  size_t     max_length;
   gchar     *pattern;
 };
 
@@ -50,7 +50,7 @@ struct _CompileTest
   const gchar *src;
   GMatchType match_type;
   gchar *pattern;
-  guint min;
+  size_t min;
 };
 
 static CompileTest compile_tests[] = {
@@ -80,8 +80,8 @@ test_compilation (gconstpointer d)
 
   g_assert_cmpint (spec->match_type, ==, test->match_type);
   g_assert_cmpstr (spec->pattern, ==, test->pattern);
-  g_assert_cmpint (spec->pattern_length, ==, strlen (spec->pattern));
-  g_assert_cmpint (spec->min_length, ==, test->min);
+  g_assert_cmpuint (spec->pattern_length, ==, strlen (spec->pattern));
+  g_assert_cmpuint (spec->min_length, ==, test->min);
 
   g_pattern_spec_free (spec);
 }
@@ -97,8 +97,8 @@ test_copy (gconstpointer d)
 
   g_assert_cmpint (p2->match_type, ==, test->match_type);
   g_assert_cmpstr (p2->pattern, ==, test->pattern);
-  g_assert_cmpint (p2->pattern_length, ==, strlen (p1->pattern));
-  g_assert_cmpint (p2->min_length, ==, test->min);
+  g_assert_cmpuint (p2->pattern_length, ==, strlen (p1->pattern));
+  g_assert_cmpuint (p2->min_length, ==, test->min);
 
   g_pattern_spec_free (p1);
   g_pattern_spec_free (p2);
@@ -186,7 +186,8 @@ test_match (gconstpointer d)
   r = g_utf8_strreverse (test->string, -1);
   g_assert_cmpint (g_pattern_spec_match (p, strlen (test->string), test->string, r), ==, test->match);
   G_GNUC_BEGIN_IGNORE_DEPRECATIONS
-  g_assert_cmpint (g_pattern_match (p, strlen (test->string), test->string, r), ==, test->match);
+  g_assert_cmpuint (strlen (test->string), <=, G_MAXUINT);
+  g_assert_cmpint (g_pattern_match (p, (guint) strlen (test->string), test->string, r), ==, test->match);
   G_GNUC_END_IGNORE_DEPRECATIONS
   g_free (r);
 
diff --git a/glib/tests/scannerapi.c b/glib/tests/scannerapi.c
index cee3956ea..715dd14d3 100644
--- a/glib/tests/scannerapi.c
+++ b/glib/tests/scannerapi.c
@@ -111,7 +111,7 @@ test_scanner_tokens (ScannerFixture *fix,
                      gconstpointer   test_data)
 {
   gchar buf[] = "(\t\n\r\\){}";
-  const gint buflen = strlen (buf);
+  const size_t buflen = strlen (buf);
   gchar tokbuf[] = "(\\){}";
   const gsize tokbuflen = strlen (tokbuf);
   gsize i;
diff --git a/glib/tests/spawn-test-win32-gui.c b/glib/tests/spawn-test-win32-gui.c
index 46353c8f3..a84fe83ff 100644
--- a/glib/tests/spawn-test-win32-gui.c
+++ b/glib/tests/spawn-test-win32-gui.c
@@ -36,7 +36,8 @@ WinMain (struct HINSTANCE__ *hInstance,
     {
       int infd = atoi (__argv[2]);
       int outfd = atoi (__argv[3]);
-      int k, n;
+      SSIZE_T k;
+      size_t n;
       char buf[100] = {0};
 
       if (infd < 0 || outfd < 0)
@@ -55,22 +56,28 @@ WinMain (struct HINSTANCE__ *hInstance,
 	  exit (1);
 	}
 
-      if ((k = read (infd, &n, sizeof (n))) != sizeof (n))
+      k = read (infd, &n, sizeof (n));
+      if (k < 0 || (size_t) k != sizeof (n))
 	{
-          fprintf (stderr, "spawn-test-win32-gui: Got only %d bytes, wanted %d\n",
-		   k, (int)sizeof (n));
+	  int errsv = errno;
+	  if (k < 0)
+            fprintf (stderr, "spawn-test-win32-gui: Read error: %s\n", strerror (errsv));
+	  else
+            fprintf (stderr, "spawn-test-win32-gui: Got only %zu bytes, wanted %zu\n",
+                     (size_t) k, sizeof (n));
 	  exit (1);
 	}
 
-      fprintf (stderr, "spawn-test-win32-gui: Parent says %d bytes to read\n", n);
+      fprintf (stderr, "spawn-test-win32-gui: Parent says %zu bytes to read\n", n);
 
-      if ((k = read (infd, buf, n)) != n)
+      k = read (infd, buf, n);
+      if (k < 0 || (size_t) k != n)
 	{
 	  int errsv = errno;
-	  if (k == -1)
+	  if (k < 0)
             fprintf (stderr, "spawn-test-win32-gui: Read error: %s\n", strerror (errsv));
 	  else
-            fprintf (stderr, "spawn-test-win32-gui: Got only %d bytes\n", k);
+            fprintf (stderr, "spawn-test-win32-gui: Got only %zu bytes\n", (size_t) k);
 	  exit (1);
 	}
 
diff --git a/glib/tests/spawn-test.c b/glib/tests/spawn-test.c
index fdc35e86f..779645a13 100644
--- a/glib/tests/spawn-test.c
+++ b/glib/tests/spawn-test.c
@@ -198,7 +198,7 @@ test_spawn_basics (void)
   gchar *output = NULL;
   gchar *erroutput = NULL;
 #ifdef G_OS_WIN32
-  int n;
+  size_t n;
   char buf[100];
   int pipedown[2], pipeup[2];
   gchar **argv = NULL;
diff --git a/glib/tests/tree.c b/glib/tests/tree.c
index 055a2c266..6e7fc0b5a 100644
--- a/glib/tests/tree.c
+++ b/glib/tests/tree.c
@@ -455,7 +455,7 @@ test_tree_insert (void)
 {
   GTree *tree;
   gchar *p;
-  gint i;
+  size_t i;
   gchar *scrambled;
 
   tree = g_tree_new (my_compare);
@@ -468,8 +468,8 @@ test_tree_insert (void)
   g_tree_unref (tree);
   tree = g_tree_new (my_compare);
 
-  for (i = strlen (chars) - 1; i >= 0; i--)
-    g_tree_insert (tree, &chars[i], &chars[i]);
+  for (i = strlen (chars); i > 0; i--)
+    g_tree_insert (tree, &chars[i - 1], &chars[i - 1]);
   p = chars;
   g_tree_foreach (tree, check_order, &p);