diff --git a/src/shell-app.c b/src/shell-app.c
index 0d314bbb3..090c6d3d2 100644
--- a/src/shell-app.c
+++ b/src/shell-app.c
@@ -1295,7 +1295,7 @@ apply_discrete_gpu_env (GAppLaunchContext *context,
   num_children = g_variant_n_children (variant);
   for (i = 0; i < num_children; i++)
     {
-      g_autoptr(GVariant) gpu;
+      g_autoptr(GVariant) gpu = NULL;
       g_autoptr(GVariant) env = NULL;
       g_autoptr(GVariant) default_variant = NULL;
       g_autofree const char **env_s = NULL;
diff --git a/src/st/st-texture-cache.c b/src/st/st-texture-cache.c
index bb614c6b4..758c0215f 100644
--- a/src/st/st-texture-cache.c
+++ b/src/st/st-texture-cache.c
@@ -142,7 +142,7 @@ on_icon_theme_changed (StSettings     *settings,
                        GParamSpec     *pspec,
                        StTextureCache *cache)
 {
-  g_autofree gchar *theme;
+  g_autofree gchar *theme = NULL;
 
   st_texture_cache_evict_icons (cache);
 
diff --git a/subprojects/extensions-tool/src/command-create.c b/subprojects/extensions-tool/src/command-create.c
index 2c140bba0..e32e7c262 100644
--- a/subprojects/extensions-tool/src/command-create.c
+++ b/subprojects/extensions-tool/src/command-create.c
@@ -89,7 +89,7 @@ create_metadata (GFile       *target_dir,
 static gboolean
 copy_extension_template (GFile *target_dir, GError **error)
 {
-  g_auto (GStrv) templates;
+  g_auto (GStrv) templates = NULL;
   char **s;
 
   templates = g_resources_enumerate_children (TEMPLATE_PATH, 0, NULL);