diff --git a/demos/gtk-demo/main.c b/demos/gtk-demo/main.c
index 286511934e..0e27a441e9 100644
--- a/demos/gtk-demo/main.c
+++ b/demos/gtk-demo/main.c
@@ -936,7 +936,7 @@ search_results_update (GObject    *filter_model,
       char *text;
 
       if (n_items > 0)
-        text = g_strdup_printf (ngettext ("%ld search result", "%ld search results", n_items), n_items);
+        text = g_strdup_printf (ngettext ("%ld search result", "%ld search results", (long) n_items), (long) n_items);
       else
         text = g_strdup (_("No search results"));
 
diff --git a/gdk/gdkvulkancontext.c b/gdk/gdkvulkancontext.c
index 8fc7a0659a..a96b2dacab 100644
--- a/gdk/gdkvulkancontext.c
+++ b/gdk/gdkvulkancontext.c
@@ -1167,7 +1167,7 @@ gdk_vulkan_save_pipeline_cache (GdkDisplay *display)
 
   file = gdk_vulkan_get_pipeline_cache_file (display);
 
-  GDK_DEBUG (VULKAN, "Saving pipeline cache of size %lu to %s", size, g_file_peek_path (file));
+  GDK_DEBUG (VULKAN, "Saving pipeline cache of size %" G_GSIZE_FORMAT " to %s", size, g_file_peek_path (file));
 
   if (!g_file_replace_contents (file,
                                 data,
@@ -1261,7 +1261,7 @@ gdk_display_create_pipeline_cache (GdkDisplay *display)
     }
   else
     {
-      GDK_DEBUG (VULKAN, "Loading pipeline cache (%lu bytes)", display->vk_pipeline_cache_size);
+      GDK_DEBUG (VULKAN, "Loading pipeline cache (%" G_GSIZE_FORMAT " bytes)", display->vk_pipeline_cache_size);
     }
 }
 
diff --git a/gdk/wayland/gdkdmabuf-wayland.c b/gdk/wayland/gdkdmabuf-wayland.c
index 2b9020153b..15d2666259 100644
--- a/gdk/wayland/gdkdmabuf-wayland.c
+++ b/gdk/wayland/gdkdmabuf-wayland.c
@@ -51,7 +51,7 @@ update_dmabuf_formats (DmabufFormatsInfo *info)
   DmabufFormats *formats = info->dmabuf_formats;
 
   GDK_DISPLAY_DEBUG (info->display, MISC,
-                     "dmabuf format table (%lu entries)", info->n_dmabuf_formats);
+                     "dmabuf format table (%" G_GSIZE_FORMAT " entries)", info->n_dmabuf_formats);
   GDK_DISPLAY_DEBUG (info->display, MISC,
                      "dmabuf main device: %u %u",
                      major (formats->main_device),
@@ -67,7 +67,7 @@ update_dmabuf_formats (DmabufFormatsInfo *info)
                          minor (tranche->target_device));
 
       GDK_DISPLAY_DEBUG (info->display, MISC,
-                         "dmabuf%s tranche (%lu entries):",
+                         "dmabuf%s tranche (%" G_GSIZE_FORMAT " entries):",
                          tranche->flags & ZWP_LINUX_DMABUF_FEEDBACK_V1_TRANCHE_FLAGS_SCANOUT ? " scanout" : "",
                          tranche->n_formats);
 
diff --git a/gtk/a11y/gtkatspicache.c b/gtk/a11y/gtkatspicache.c
index c24d55923f..de60110008 100644
--- a/gtk/a11y/gtkatspicache.c
+++ b/gtk/a11y/gtkatspicache.c
@@ -304,7 +304,7 @@ handle_cache_method (GDBusConnection       *connection,
 
       self->in_get_items = FALSE;
 
-      GTK_DEBUG (A11Y, "Returning %lu items", g_variant_n_children (items));
+      GTK_DEBUG (A11Y, "Returning %" G_GSIZE_FORMAT " items", g_variant_n_children (items));
 
       g_dbus_method_invocation_return_value (invocation, items);
     }
diff --git a/gtk/css/gtkcssparser.c b/gtk/css/gtkcssparser.c
index 40ec881ea7..778fac1f0d 100644
--- a/gtk/css/gtkcssparser.c
+++ b/gtk/css/gtkcssparser.c
@@ -242,7 +242,7 @@ gtk_css_parser_finalize (GtkCssParser *self)
   g_clear_object (&self->file);
   g_clear_object (&self->directory);
   if (gtk_css_parser_blocks_get_size (&self->blocks) > 0)
-    g_critical ("Finalizing CSS parser with %lu remaining blocks", gtk_css_parser_blocks_get_size (&self->blocks));
+    g_critical ("Finalizing CSS parser with %" G_GSIZE_FORMAT " remaining blocks", gtk_css_parser_blocks_get_size (&self->blocks));
   gtk_css_parser_blocks_clear (&self->blocks);
 
   g_free (self);
diff --git a/testsuite/gdk/colorstate.c b/testsuite/gdk/colorstate.c
index a5b4fcc109..eefb6dc8f4 100644
--- a/testsuite/gdk/colorstate.c
+++ b/testsuite/gdk/colorstate.c
@@ -105,7 +105,7 @@ image_distance (const guchar *data,
   if (g_test_verbose() &&
       dist > 0)
     {
-      g_print ("worst pixel %lu %lu: %f %f %f %f  vs  %f %f %f %f\n",
+      g_print ("worst pixel %" G_GSIZE_FORMAT " %" G_GSIZE_FORMAT ": %f %f %f %f  vs  %f %f %f %f\n",
                imax, jmax, r1, g1, b1, a1, r2, g2, b2, a2);
     }