diff --git a/embassy-stm32/src/adc/v2.rs b/embassy-stm32/src/adc/v2.rs
index a74c00979..9244e5d8b 100644
--- a/embassy-stm32/src/adc/v2.rs
+++ b/embassy-stm32/src/adc/v2.rs
@@ -196,7 +196,7 @@ where
         self.resolution = resolution;
     }
 
-    /// Set VREF, which is used for [to_millivolts()] conversion.
+    /// Set VREF value in millivolts. This value is used for [to_millivolts()] sample conversion.
     ///
     /// Use this if you have a known precise VREF (VDDA) pin reference voltage.
     pub fn set_vref(&mut self, vref: u32) {
diff --git a/embassy-stm32/src/adc/v3.rs b/embassy-stm32/src/adc/v3.rs
index 32e115fa1..d8cac0724 100644
--- a/embassy-stm32/src/adc/v3.rs
+++ b/embassy-stm32/src/adc/v3.rs
@@ -318,7 +318,7 @@ impl<'d, T: Instance> Adc<'d, T> {
         self.resolution = resolution;
     }
 
-    /// Set VREF used for [to_millivolts()] conversion.
+    /// Set VREF value in millivolts. This value is used for [to_millivolts()] sample conversion.
     ///
     /// Use this if you have a known precise VREF (VDDA) pin reference voltage.
     pub fn set_vref(&mut self, vref: u32) {
diff --git a/embassy-stm32/src/adc/v4.rs b/embassy-stm32/src/adc/v4.rs
index 0950b4661..cc210a6d0 100644
--- a/embassy-stm32/src/adc/v4.rs
+++ b/embassy-stm32/src/adc/v4.rs
@@ -467,7 +467,7 @@ impl<'d, T: Instance + crate::rcc::RccPeripheral> Adc<'d, T> {
         self.resolution = resolution;
     }
 
-    /// Set VREF used for [to_millivolts()] conversion.
+    /// Set VREF value in millivolts. This value is used for [to_millivolts()] sample conversion.
     ///
     /// Use this if you have a known precise VREF (VDDA) pin reference voltage.
     pub fn set_vref(&mut self, vref: u32) {