diff --git a/src/host/wasapi/device.rs b/src/host/wasapi/device.rs
index f57ba04..3093b10 100644
--- a/src/host/wasapi/device.rs
+++ b/src/host/wasapi/device.rs
@@ -552,7 +552,7 @@ impl Device {
         }
     }
 
-    fn data_flow(&self) -> EDataFlow {
+    pub(crate) fn data_flow(&self) -> EDataFlow {
         let endpoint = Endpoint::from(self.device as *const _);
         endpoint.data_flow()
     }
diff --git a/src/host/wasapi/mod.rs b/src/host/wasapi/mod.rs
index eadeb95..239adbf 100644
--- a/src/host/wasapi/mod.rs
+++ b/src/host/wasapi/mod.rs
@@ -21,6 +21,10 @@ mod device;
 mod stream;
 
 /// The WASAPI host, the default windows host type.
+///
+/// Note: If you use a WASAPI output device as an input device it will
+/// transparently enable loopback mode (see
+/// https://docs.microsoft.com/en-us/windows/win32/coreaudio/loopback-recording).
 #[derive(Debug)]
 pub struct Host;
 
diff --git a/src/host/wasapi/stream.rs b/src/host/wasapi/stream.rs
index 15382a0..bd20ba8 100644
--- a/src/host/wasapi/stream.rs
+++ b/src/host/wasapi/stream.rs
@@ -6,7 +6,8 @@ use super::winapi::shared::ksmedia;
 use super::winapi::shared::minwindef::{BYTE, DWORD, FALSE, WORD};
 use super::winapi::shared::mmreg;
 use super::winapi::um::audioclient::{self, AUDCLNT_E_DEVICE_INVALIDATED, AUDCLNT_S_BUFFER_EMPTY};
-use super::winapi::um::audiosessiontypes::{AUDCLNT_SHAREMODE_SHARED, AUDCLNT_STREAMFLAGS_EVENTCALLBACK};
+use super::winapi::um::audiosessiontypes::{AUDCLNT_SHAREMODE_SHARED, AUDCLNT_STREAMFLAGS_EVENTCALLBACK, AUDCLNT_STREAMFLAGS_LOOPBACK};
+use super::winapi::um::mmdeviceapi::eRender;
 use super::winapi::um::handleapi;
 use super::winapi::um::synchapi;
 use super::winapi::um::winbase;
@@ -151,10 +152,16 @@ impl EventLoop {
                     _ => (),
                 }
 
+                // Support capturing output devices.
+                let mut stream_flags: DWORD = AUDCLNT_STREAMFLAGS_EVENTCALLBACK;
+                if device.data_flow() == eRender {
+                    stream_flags |= AUDCLNT_STREAMFLAGS_LOOPBACK;
+                }
+
                 // finally initializing the audio client
                 let hresult = (*audio_client).Initialize(
                     share_mode,
-                    AUDCLNT_STREAMFLAGS_EVENTCALLBACK,
+                    stream_flags,
                     0,
                     0,
                     &format_attempt.Format,