diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index 6de869fa81c..01346f17ca7 100644
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -3911,15 +3911,18 @@ bitint_large_huge::lower_addsub_overflow (tree obj, gimple *stmt)
 
   tree type0 = TREE_TYPE (arg0);
   tree type1 = TREE_TYPE (arg1);
-  if (TYPE_PRECISION (type0) < prec3)
+  int prec5 = prec3;
+  if (bitint_precision_kind (prec5) < bitint_prec_large)
+    prec5 = MAX (TYPE_PRECISION (type0), TYPE_PRECISION (type1));
+  if (TYPE_PRECISION (type0) < prec5)
     {
-      type0 = build_bitint_type (prec3, TYPE_UNSIGNED (type0));
+      type0 = build_bitint_type (prec5, TYPE_UNSIGNED (type0));
       if (TREE_CODE (arg0) == INTEGER_CST)
 	arg0 = fold_convert (type0, arg0);
     }
-  if (TYPE_PRECISION (type1) < prec3)
+  if (TYPE_PRECISION (type1) < prec5)
     {
-      type1 = build_bitint_type (prec3, TYPE_UNSIGNED (type1));
+      type1 = build_bitint_type (prec5, TYPE_UNSIGNED (type1));
       if (TREE_CODE (arg1) == INTEGER_CST)
 	arg1 = fold_convert (type1, arg1);
     }
diff --git a/gcc/testsuite/gcc.dg/bitint-46.c b/gcc/testsuite/gcc.dg/bitint-46.c
new file mode 100644
index 00000000000..4e503376d7f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-46.c
@@ -0,0 +1,32 @@
+/* PR middle-end/112807 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=gnu23 -O2" } */
+
+#if __BITINT_MAXWIDTH__ >= 256
+__attribute__((noipa)) int
+foo (_BitInt (256) a, _BitInt (2) b)
+{
+  if (a < 0 || a > ~0U)
+    return -1;
+  return __builtin_sub_overflow_p (a, b, 0);
+}
+#endif
+
+int
+main ()
+{
+#if __BITINT_MAXWIDTH__ >= 256
+  if (foo (-5wb, 1wb) != -1
+      || foo (1 + (_BitInt (256)) ~0U, -2) != -1
+      || foo (0, 0) != 0
+      || foo (0, 1) != 0
+      || foo (0, -1) != 0
+      || foo (~0U, 0) != 1
+      || foo (__INT_MAX__, 0) != 0
+      || foo (__INT_MAX__, -1) != 1
+      || foo (1 + (_BitInt (256)) __INT_MAX__, 0) != 1
+      || foo (1 + (_BitInt (256)) __INT_MAX__, 1) != 0
+      || foo (1 + (_BitInt (256)) __INT_MAX__, -2) != 1)
+    __builtin_abort ();
+#endif
+}