diff --git a/crates/eframe/src/native/glow_integration.rs b/crates/eframe/src/native/glow_integration.rs
index a087c9fa..4a3bee46 100644
--- a/crates/eframe/src/native/glow_integration.rs
+++ b/crates/eframe/src/native/glow_integration.rs
@@ -563,6 +563,12 @@ impl GlowWinitRunning<'_> {
             (raw_input, viewport_ui_cb)
         };
 
+        // HACK: In order to get the right clear_color, the system theme needs to be set, which
+        // usually only happens in the `update` call. So we call Options::begin_pass early
+        // to set the right theme. Without this there would be a black flash on the first frame.
+        self.integration
+            .egui_ctx
+            .options_mut(|opt| opt.begin_pass(&raw_input));
         let clear_color = self
             .app
             .clear_color(&self.integration.egui_ctx.style().visuals);
diff --git a/crates/egui/src/memory/mod.rs b/crates/egui/src/memory/mod.rs
index cab041bf..ddc5a9ff 100644
--- a/crates/egui/src/memory/mod.rs
+++ b/crates/egui/src/memory/mod.rs
@@ -318,7 +318,9 @@ impl Default for Options {
 }
 
 impl Options {
-    pub(crate) fn begin_pass(&mut self, new_raw_input: &RawInput) {
+    // Needs to be pub because we need to set the system_theme early in the eframe glow renderer.
+    #[doc(hidden)]
+    pub fn begin_pass(&mut self, new_raw_input: &RawInput) {
         self.system_theme = new_raw_input.system_theme;
     }