diff --git a/internal/staticsources/mpegts/source_test.go b/internal/staticsources/mpegts/source_test.go
index 18a5664a..ecd8b3bd 100644
--- a/internal/staticsources/mpegts/source_test.go
+++ b/internal/staticsources/mpegts/source_test.go
@@ -1,6 +1,7 @@
 package mpegts
 
 import (
+	"bufio"
 	"context"
 	"net"
 	"os"
@@ -117,7 +118,8 @@ func TestSourceUDP(t *testing.T) {
 				Codec: &tscodecs.H264{},
 			}
 
-			w := &mpegts.Writer{W: conn, Tracks: []*mpegts.Track{track}}
+			bw := bufio.NewWriter(conn)
+			w := &mpegts.Writer{W: bw, Tracks: []*mpegts.Track{track}}
 			err = w.Initialize()
 			require.NoError(t, err)
 
@@ -126,11 +128,17 @@ func TestSourceUDP(t *testing.T) {
 			}})
 			require.NoError(t, err)
 
+			err = bw.Flush()
+			require.NoError(t, err)
+
 			err = w.WriteH264(track, 0, 0, [][]byte{{ // non-IDR
 				5, 2,
 			}})
 			require.NoError(t, err)
 
+			err = bw.Flush()
+			require.NoError(t, err)
+
 			<-p.Unit
 
 			// the source must be listening on ReloadConf
@@ -189,7 +197,8 @@ func TestSourceUnixSocket(t *testing.T) {
 					Codec: &tscodecs.H264{},
 				}
 
-				w := &mpegts.Writer{W: conn, Tracks: []*mpegts.Track{track}}
+				bw := bufio.NewWriter(conn)
+				w := &mpegts.Writer{W: bw, Tracks: []*mpegts.Track{track}}
 				err = w.Initialize()
 				require.NoError(t, err)
 
@@ -198,6 +207,9 @@ func TestSourceUnixSocket(t *testing.T) {
 				}})
 				require.NoError(t, err)
 
+				err = bw.Flush()
+				require.NoError(t, err)
+
 				conn.Close() // trigger a flush
 
 				<-p.Unit
diff --git a/internal/staticsources/srt/source_test.go b/internal/staticsources/srt/source_test.go
index 7d033c41..d6ce1dd6 100644
--- a/internal/staticsources/srt/source_test.go
+++ b/internal/staticsources/srt/source_test.go
@@ -1,6 +1,7 @@
 package srt
 
 import (
+	"bufio"
 	"context"
 	"testing"
 	"time"
@@ -59,7 +60,8 @@ func TestSource(t *testing.T) {
 
 	track := &mpegts.Track{Codec: &tscodecs.H264{}}
 
-	w := &mpegts.Writer{W: conn, Tracks: []*mpegts.Track{track}}
+	bw := bufio.NewWriter(conn)
+	w := &mpegts.Writer{W: bw, Tracks: []*mpegts.Track{track}}
 	err2 = w.Initialize()
 	require.NoError(t, err2)
 
@@ -68,11 +70,17 @@ func TestSource(t *testing.T) {
 	}})
 	require.NoError(t, err2)
 
+	err = bw.Flush()
+	require.NoError(t, err)
+
 	err = w.WriteH264(track, 0, 0, [][]byte{{ // non-IDR
 		5, 2,
 	}})
 	require.NoError(t, err)
 
+	err = bw.Flush()
+	require.NoError(t, err)
+
 	<-p.Unit
 
 	// the source must be listening on ReloadConf