diff --git a/interpreters/micropython/micropython_main.c b/interpreters/micropython/micropython_main.c
index 24bb12edf..0d68e815b 100644
--- a/interpreters/micropython/micropython_main.c
+++ b/interpreters/micropython/micropython_main.c
@@ -149,39 +149,6 @@ float nanf(FAR const char *tagp)
   return 0;
 }
 
-float truncf(float x)
-{
-  union
-    {
-      float f;
-      uint32_t i;
-    } u =
-  {
-  x};
-  int e = (int)(u.i >> 23 & 0xff) - 0x7f + 9;
-  uint32_t m;
-
-  if (e >= 23 + 9)
-    {
-      return x;
-    }
-
-  if (e < 9)
-    {
-      e = 1;
-    }
-
-  m = -1U >> e;
-  if ((u.i & m) == 0)
-    {
-      return x;
-    }
-
-  FORCE_EVAL(x + 0x1p120f);
-  u.i &= ~m;
-  return u.f;
-}
-
 /****************************************************************************
  * mp_import_stat
  ****************************************************************************/