diff --git a/mingw.c b/mingw.c
index 956978f2..b1a5af7b 100644
--- a/mingw.c
+++ b/mingw.c
@@ -694,5 +694,10 @@ const char* windows_stat_desc(struct stat* st)
 	return st->st_desc;
 }
 
+void windows_sleep(unsigned seconds)
+{
+	Sleep(seconds * 1000);
+}
+
 #endif
 
diff --git a/mingw.h b/mingw.h
index 88158700..9d08d6f7 100644
--- a/mingw.h
+++ b/mingw.h
@@ -54,6 +54,7 @@
 #define O_NOFOLLOW 0
 #define stat_hidden windows_stat_hidden
 #define stat_desc windows_stat_desc
+#define sleep windows_sleep
 /* In Windows symbolic links are not supported */
 #define S_ISLNK(mode) 0
 #define readlink(a,b,c) -1
@@ -213,6 +214,11 @@ int windows_stat_hidden(struct dirent* dd, struct windows_stat* st);
  */
 const char* windows_stat_desc(struct stat* st);
 
+/**
+ * Like sleep().
+ */
+void windows_sleep(unsigned seconds);
+
 #endif
 #endif
 
diff --git a/snapraid.c b/snapraid.c
index 6e0f6bb8..30a60927 100644
--- a/snapraid.c
+++ b/snapraid.c
@@ -307,6 +307,16 @@ int main(int argc, char* argv[])
 		if (state.need_write)
 			state_write(&state);
 
+		/* waits some time to ensure that any concurrent modification done at the files, */
+		/* using the same mtime read by the scan process, will be read by sync. */
+		/* Note that any later modification done, potentially not read by sync, will have */
+		/* a different mtime, and it will be syncronized at the next sync. */
+		/* The worst case is the FAT filesystem with a two seconds resolution for mtime. */
+		/* If you don't use FAT, the wait is not needed, because most filesystems have now */
+		/* at least microseconds resolution, but better to be safe. */
+		if (!test_skip_self)
+			sleep(2);
+
 		ret = state_sync(&state, blockstart, blockcount);
 
 		/* save the new state if required */