diff --git a/libgimp/gimpproceduredialog.c b/libgimp/gimpproceduredialog.c
index 187e30616b..212db10a52 100644
--- a/libgimp/gimpproceduredialog.c
+++ b/libgimp/gimpproceduredialog.c
@@ -993,7 +993,7 @@ gimp_procedure_dialog_fill_list (GimpProcedureDialog *dialog,
     {
       GParamSpec **pspecs;
       guint        n_pspecs;
-      gint         i;
+      guint        i;
 
       pspecs = g_object_class_list_properties (G_OBJECT_GET_CLASS (dialog->priv->config),
                                                &n_pspecs);
@@ -1661,7 +1661,7 @@ gimp_procedure_dialog_fill_container_list (GimpProcedureDialog *dialog,
     {
       GParamSpec **pspecs;
       guint        n_pspecs;
-      gint         i;
+      guint        i;
 
       pspecs = g_object_class_list_properties (G_OBJECT_GET_CLASS (dialog->priv->config),
                                                &n_pspecs);
diff --git a/libgimp/gimptilebackendplugin.c b/libgimp/gimptilebackendplugin.c
index 3d429555e9..93e39e6a84 100644
--- a/libgimp/gimptilebackendplugin.c
+++ b/libgimp/gimptilebackendplugin.c
@@ -232,9 +232,9 @@ gimp_tile_read (GimpTileBackendPlugin *backend_plugin,
     }
   else
     {
-      gint tile_stride      = TILE_WIDTH * priv->bpp;
-      gint gimp_tile_stride = gimp_tile.ewidth * priv->bpp;
-      gint row;
+      gint  tile_stride      = TILE_WIDTH * priv->bpp;
+      gint  gimp_tile_stride = gimp_tile.ewidth * priv->bpp;
+      guint row;
 
       for (row = 0; row < gimp_tile.eheight; row++)
         {
@@ -277,9 +277,9 @@ gimp_tile_write (GimpTileBackendPlugin *backend_plugin,
     }
   else
     {
-      gint tile_stride      = TILE_WIDTH * priv->bpp;
-      gint gimp_tile_stride = gimp_tile.ewidth * priv->bpp;
-      gint row;
+      gint  tile_stride      = TILE_WIDTH * priv->bpp;
+      gint  gimp_tile_stride = gimp_tile.ewidth * priv->bpp;
+      guint row;
 
       for (row = 0; row < gimp_tile.eheight; row++)
         {
diff --git a/libgimpbase/gimpprotocol.c b/libgimpbase/gimpprotocol.c
index 1b458121be..3d904bada8 100644
--- a/libgimpbase/gimpprotocol.c
+++ b/libgimpbase/gimpprotocol.c
@@ -1538,7 +1538,7 @@ _gp_params_read (GIOChannel  *channel,
                  guint       *n_params,
                  gpointer     user_data)
 {
-  gint i;
+  guint i;
 
   if (! _gimp_wire_read_int32 (channel, (guint32 *) n_params, 1, user_data))
     return;
diff --git a/libgimpbase/gimpvaluearray.c b/libgimpbase/gimpvaluearray.c
index d0bbc867c6..eb21d2fd85 100644
--- a/libgimpbase/gimpvaluearray.c
+++ b/libgimpbase/gimpvaluearray.c
@@ -675,7 +675,7 @@ gimp_param_value_array_values_cmp (GParamSpec   *pspec,
     }
   else /* length1 == length2 */
     {
-      guint i;
+      gint i;
 
       for (i = 0; i < length1; i++)
         {
diff --git a/libgimpconfig/gimpconfig-path.c b/libgimpconfig/gimpconfig-path.c
index 86c258de1d..4ac713d64c 100644
--- a/libgimpconfig/gimpconfig-path.c
+++ b/libgimpconfig/gimpconfig-path.c
@@ -528,7 +528,7 @@ gimp_config_path_expand_only (const gchar  *path,
   gchar      **substs   = NULL;
   guint        n_substs = 0;
   gint         length   = 0;
-  gint         i;
+  guint        i;
 
   home = g_get_home_dir ();
   if (home)
diff --git a/libgimpconfig/gimpconfig-utils.c b/libgimpconfig/gimpconfig-utils.c
index 7461e784b2..5b5f11ea8f 100644
--- a/libgimpconfig/gimpconfig-utils.c
+++ b/libgimpconfig/gimpconfig-utils.c
@@ -89,7 +89,7 @@ gimp_config_diff_same (GObject     *a,
 {
   GParamSpec **param_specs;
   guint        n_param_specs;
-  gint         i;
+  guint        i;
   GList       *list = NULL;
 
   param_specs = g_object_class_list_properties (G_OBJECT_GET_CLASS (a),
@@ -118,7 +118,7 @@ gimp_config_diff_other (GObject     *a,
 {
   GParamSpec **param_specs;
   guint        n_param_specs;
-  gint         i;
+  guint        i;
   GList       *list = NULL;
 
   param_specs = g_object_class_list_properties (G_OBJECT_GET_CLASS (a),
diff --git a/libgimpthumb/gimpthumb-utils.c b/libgimpthumb/gimpthumb-utils.c
index 833d684bf1..9d0886ce3c 100644
--- a/libgimpthumb/gimpthumb-utils.c
+++ b/libgimpthumb/gimpthumb-utils.c
@@ -103,7 +103,7 @@ gimp_thumb_init (const gchar *creator,
 {
   GEnumClass *enum_class;
   GEnumValue *enum_value;
-  gint        i;
+  guint        i;
 
   g_return_val_if_fail (creator != NULL, FALSE);
   g_return_val_if_fail (thumb_basedir == NULL ||
diff --git a/libgimpwidgets/gimpcolorarea.c b/libgimpwidgets/gimpcolorarea.c
index e4913a0c00..ffa334e70e 100644
--- a/libgimpwidgets/gimpcolorarea.c
+++ b/libgimpwidgets/gimpcolorarea.c
@@ -395,7 +395,7 @@ gimp_color_area_draw (GtkWidget *widget,
       guchar     *buf    = g_new (guchar, priv->rowstride * priv->height);
       guchar     *src    = priv->buf;
       guchar     *dest   = buf;
-      gint        i;
+      guint       i;
 
       for (i = 0; i < priv->height; i++)
         {
diff --git a/libgimpwidgets/gimpcolorscale.c b/libgimpwidgets/gimpcolorscale.c
index 67770e147b..7d4f6ffc45 100644
--- a/libgimpwidgets/gimpcolorscale.c
+++ b/libgimpwidgets/gimpcolorscale.c
@@ -339,7 +339,7 @@ gimp_color_scale_draw (GtkWidget *widget,
       guchar     *buf    = g_new (guchar, priv->rowstride * priv->height);
       guchar     *src    = priv->buf;
       guchar     *dest   = buf;
-      gint        i;
+      guint       i;
 
       for (i = 0; i < priv->height; i++)
         {
diff --git a/plug-ins/common/animation-optimize.c b/plug-ins/common/animation-optimize.c
index dea6cd5fdc..f30b3cf3ee 100644
--- a/plug-ins/common/animation-optimize.c
+++ b/plug-ins/common/animation-optimize.c
@@ -570,7 +570,8 @@ do_optimizations (GimpRunMode  run_mode,
     {
       /* iterate through all rows of all frames, find statistical
          mode for each pixel position. */
-      gint     i,j;
+      gint     i;
+      guint    j;
       guchar **these_rows;
       guchar **red;
       guchar **green;
diff --git a/plug-ins/common/file-gif-save.c b/plug-ins/common/file-gif-save.c
index 161e850d4c..9da6d5a533 100644
--- a/plug-ins/common/file-gif-save.c
+++ b/plug-ins/common/file-gif-save.c
@@ -554,7 +554,7 @@ special_flatten_indexed_alpha (guchar *pixels,
                                gint    transparent,
                                gint    numpixels)
 {
-  guint32 i;
+  gint i;
 
   /* Each transparent pixel in the image is mapped to a uniform value
    * for encoding, if image already has <=255 colors
diff --git a/plug-ins/common/file-gih.c b/plug-ins/common/file-gih.c
index 1c3d132cf6..2f6062a973 100644
--- a/plug-ins/common/file-gih.c
+++ b/plug-ins/common/file-gih.c
@@ -806,7 +806,7 @@ gih_save_dialog (GimpImage *image)
   gtk_grid_set_column_spacing (GTK_GRID (dimgrid), 4);
   for (i = 0; i < GIMP_PIXPIPE_MAXDIM; i++)
     {
-      gint j;
+      gsize j;
 
       adjustment = gtk_adjustment_new (gihparams.rank[i], 1, 100, 1, 1, 0);
       spinbutton = gimp_spin_button_new (adjustment, 1.0, 0);
diff --git a/plug-ins/file-psd/psd-save.c b/plug-ins/file-psd/psd-save.c
index 6bec383208..9ba232ac60 100644
--- a/plug-ins/file-psd/psd-save.c
+++ b/plug-ins/file-psd/psd-save.c
@@ -1529,7 +1529,7 @@ write_pixel_data (GOutputStream  *output,
         {
           write_gint16 (output, 1, "Compression type (RLE)");
           len += 2;
-          IF_DEEP_DBG printf ("\t\t\t\t. ChanLenPos, len %d\n", len);
+          IF_DEEP_DBG printf ("\t\t\t\t. ChanLenPos, len %ld\n", len);
         }
 
       if (ltable_offset > 0)
diff --git a/plug-ins/metadata/metadata-editor.c b/plug-ins/metadata/metadata-editor.c
index 527dd55d40..efd678c74d 100644
--- a/plug-ins/metadata/metadata-editor.c
+++ b/plug-ins/metadata/metadata-editor.c
@@ -942,7 +942,7 @@ on_date_button_clicked (GtkButton *widget,
   date_text = gtk_entry_get_text (GTK_ENTRY (entry_widget));
   if (date_text && date_text[0] != '\0')
     {
-      sscanf (date_text, "%d-%d-%d;", &year, &month, &day);
+      sscanf (date_text, "%u-%u-%u;", &year, &month, &day);
       month--;
     }
   else