diff --git a/include/platform.h b/include/platform.h
index 1706b1847..026ebbe17 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -481,9 +481,14 @@ typedef unsigned smalluint;
 
 #if defined(ANDROID) || defined(__ANDROID__)
 # if __ANDROID_API__ < 8
+   /* ANDROID < 8 has no [f]dprintf at all */
 #  undef HAVE_DPRINTF
-# else
+# elif __ANDROID_API__ < 21
+   /* ANDROID < 21 has fdprintf */
 #  define dprintf fdprintf
+# else
+   /* ANDROID >= 21 has standard dprintf */
+# endif
 # endif
 # if __ANDROID_API__ < 21
 #  undef HAVE_TTYNAME_R
diff --git a/libbb/missing_syscalls.c b/libbb/missing_syscalls.c
index e3c1e924b..093412811 100644
--- a/libbb/missing_syscalls.c
+++ b/libbb/missing_syscalls.c
@@ -40,8 +40,10 @@ int pivot_root(const char *new_root, const char *put_old)
 	return syscall(__NR_pivot_root, new_root, put_old);
 }
 
+# if __ANDROID_API__ < 21
 int tcdrain(int fd)
 {
 	return ioctl(fd, TCSBRK, 1);
 }
+# endif
 #endif