diff --git a/embassy-stm32/src/rcc/l4.rs b/embassy-stm32/src/rcc/l4.rs
index 36c9eb2f..b2828e58 100644
--- a/embassy-stm32/src/rcc/l4.rs
+++ b/embassy-stm32/src/rcc/l4.rs
@@ -10,6 +10,7 @@ use crate::gpio::Speed;
 use crate::pac::rcc::vals::{Hpre, Msirange, Pllsrc, Ppre, Sw};
 use crate::pac::{FLASH, PWR, RCC};
 use crate::rcc::{set_freqs, Clocks};
+use crate::rtc::{Rtc, RtcClockSource as RCS};
 use crate::time::Hertz;
 use crate::{peripherals, Peripheral};
 
@@ -426,6 +427,8 @@ pub(crate) unsafe fn init(config: Config) {
 
             // Wait until LSE is running
             while !RCC.bdcr().read().lserdy() {}
+
+            Rtc::set_clock_source(RCS::LSE);
         }
         RtcClockSource::LSI32 => {
             // Turn on the internal 32 kHz LSI oscillator
@@ -433,6 +436,8 @@ pub(crate) unsafe fn init(config: Config) {
 
             // Wait until LSI is running
             while !RCC.csr().read().lsirdy() {}
+
+            Rtc::set_clock_source(RCS::LSI);
         }
     }
 
diff --git a/examples/stm32l4/src/bin/rtc.rs b/examples/stm32l4/src/bin/rtc.rs
index fe2aabb4..294ea456 100644
--- a/examples/stm32l4/src/bin/rtc.rs
+++ b/examples/stm32l4/src/bin/rtc.rs
@@ -33,10 +33,7 @@ async fn main(_spawner: Spawner) {
         .and_hms_opt(10, 30, 15)
         .unwrap();
 
-    let mut rtc = Rtc::new(
-        p.RTC,
-        RtcConfig::default().clock_source(embassy_stm32::rtc::RtcClockSource::LSE),
-    );
+    let mut rtc = Rtc::new(p.RTC, RtcConfig::default());
     info!("Got RTC! {:?}", now.timestamp());
 
     rtc.set_datetime(now.into()).expect("datetime not set");