diff --git a/libavformat/img2dec.c b/libavformat/img2dec.c
index 15fd67927f..2761cb37a4 100644
--- a/libavformat/img2dec.c
+++ b/libavformat/img2dec.c
@@ -36,6 +36,7 @@
 #include "avio_internal.h"
 #include "internal.h"
 #include "img2.h"
+#include "os_support.h"
 #include "libavcodec/jpegxl_parse.h"
 #include "libavcodec/mjpeg.h"
 #include "libavcodec/vbn.h"
diff --git a/libavformat/internal.h b/libavformat/internal.h
index 594afd731d..53e70ccb53 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -26,7 +26,6 @@
 #include "libavcodec/packet_internal.h"
 
 #include "avformat.h"
-#include "os_support.h"
 
 #define MAX_URL_SIZE 4096
 
diff --git a/libavformat/rtsp.h b/libavformat/rtsp.h
index 6e500fd56a..83b2e3f4fb 100644
--- a/libavformat/rtsp.h
+++ b/libavformat/rtsp.h
@@ -28,6 +28,7 @@
 #include "network.h"
 #include "httpauth.h"
 #include "internal.h"
+#include "os_support.h"
 
 #include "libavutil/log.h"
 #include "libavutil/opt.h"
diff --git a/libavformat/utils.c b/libavformat/utils.c
index cf4d68bff9..c722743744 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -37,6 +37,7 @@
 #if CONFIG_NETWORK
 #include "network.h"
 #endif
+#include "os_support.h"
 
 static AVMutex avformat_mutex = AV_MUTEX_INITIALIZER;