diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index 378342bbb..bf440936c 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -7521,6 +7521,12 @@
     exec->func_round = (TT_Round_Func)Round_To_Grid;
     Compute_Funcs( exec );
 
+#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
+    /* Reset IUP tracking bits in the backward compatibility mode. */
+    /* See `ttinterp.h' for details.                               */
+    exc->backward_compatibility &= ~0x6;
+#endif
+
     /* some glyphs leave something on the stack, */
     /* so we clean it before a new execution.    */
     exec->top     = 0;