diff --git a/src/main.rs b/src/main.rs
index addb660..011daf4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -28,15 +28,23 @@ async fn main(_spawner: Spawner) {
     let mut config = Config::default();
     {
         use embassy_stm32::rcc::*;
+        config.rcc.hsi = None;
+        config.rcc.hsi48 = Some(Hsi48Config { sync_from_usb: true }); // needed for USB
+        config.rcc.hse = Some(Hse {
+            freq: Hertz(24_000_000),
+            mode: HseMode::Oscillator,
+        });
         config.rcc.pll1 = Some(Pll {
-            source: PllSource::HSI,
-            prediv: PllPreDiv::DIV4,
-            mul: PllMul::MUL8,
+            source: PllSource::HSE,
+            prediv: PllPreDiv::DIV6,
+            mul: PllMul::MUL125,
             divp: Some(PllDiv::DIV2),
             divq: Some(PllDiv::DIV2),
             divr: Some(PllDiv::DIV2),
-        })
-    }
+        });
+        config.rcc.sys = Sysclk::PLL1_P;
+        config.rcc.mux.usbsel = mux::Usbsel::HSI48;
+    }    
 
     let p = embassy_stm32::init(config);
     info!("Hello World!");