diff --git a/meson.build b/meson.build
index b97d9c9..9f8397c 100644
--- a/meson.build
+++ b/meson.build
@@ -1,10 +1,10 @@
-project(
-  'vipsdisp', 'c',
+project('vipsdisp', 'c',
   version: '3.1.0',
   license: 'MIT',
   meson_version: '>=0.56',
   default_options: [
-    'c_std=c11',
+    # glib uses this, so we do too
+    'c_std=gnu11',
     # do a release (optimised) build by default
     'buildtype=release',
     # turn off asserts etc. in release mode
diff --git a/src/imageui.c b/src/imageui.c
index f4fcc00..b10e5fa 100644
--- a/src/imageui.c
+++ b/src/imageui.c
@@ -157,6 +157,8 @@ imageui_set_property(GObject *object,
 {
 	Imageui *imageui = (Imageui *) object;
 
+    double zoom;
+
 #ifdef DEBUG_VERBOSE
 	{
 		g_autofree char *str = g_strdup_value_contents(value);
@@ -179,7 +181,7 @@ imageui_set_property(GObject *object,
 	case PROP_ZOOM:
 		/* Scale by the zoom factor (SVG etc. zoom) we picked on load.
 		 */
-		double zoom = g_value_get_double(value);
+		zoom = g_value_get_double(value);
 		zoom /= imageui->tilesource->zoom;
 
 		g_object_set(imageui->imagedisplay, 
@@ -209,6 +211,8 @@ imageui_get_property(GObject *object,
 {
 	Imageui *imageui = IMAGEUI(object);
 
+    double zoom;
+
 	switch (prop_id) {
 	case PROP_TILESOURCE:
 		g_value_set_object(value, imageui->tilesource);
@@ -220,8 +224,6 @@ imageui_get_property(GObject *object,
 		break;
 
 	case PROP_ZOOM:
-		double zoom;
-
 		g_object_get(imageui->imagedisplay,
 			"zoom", &zoom,
 			NULL);
diff --git a/src/tilesource.c b/src/tilesource.c
index 8aa5b9a..9e5316f 100644
--- a/src/tilesource.c
+++ b/src/tilesource.c
@@ -783,6 +783,7 @@ tilesource_set_property(GObject *object,
 	int i;
 	double d;
 	gboolean b;
+    TilesourceMode mode;
 
 #ifdef DEBUG
 	{
@@ -794,7 +795,7 @@ tilesource_set_property(GObject *object,
 
 	switch (prop_id) {
 	case PROP_MODE:
-		TilesourceMode mode = g_value_get_enum(value);
+		mode = g_value_get_enum(value);
 		if (mode >= 0 &&
 			mode < TILESOURCE_MODE_LAST &&
 			tilesource->mode != mode) {