diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index 13b9b205df7..fb03063f86e 100644
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -4497,7 +4497,7 @@ bitint_large_huge::lower_mul_overflow (tree obj, gimple *stmt)
 					   size_one_node);
 		  insert_before (g);
 		  g = gimple_build_cond (NE_EXPR, idx_next,
-					 size_int (endlimb + (cnt == 1)),
+					 size_int (endlimb + (cnt == 2)),
 					 NULL_TREE, NULL_TREE);
 		  insert_before (g);
 		  edge true_edge, false_edge;
diff --git a/gcc/testsuite/gcc.dg/torture/bitint-59.c b/gcc/testsuite/gcc.dg/torture/bitint-59.c
new file mode 100644
index 00000000000..ef17424dfa8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/bitint-59.c
@@ -0,0 +1,22 @@
+/* PR tree-optimization/114038 */
+/* { dg-do run { target bitint } } */
+/* { dg-options "-std=c23 -pedantic-errors" } */
+/* { dg-skip-if "" { ! run_expensive_tests }  { "*" } { "-O0" "-O2" } } */
+/* { dg-skip-if "" { ! run_expensive_tests } { "-flto" } { "" } } */
+
+#if __BITINT_MAXWIDTH__ >= 129
+int
+foo (unsigned _BitInt(63) x, unsigned _BitInt(129) y)
+{
+  return __builtin_mul_overflow_p (y, x, 0);
+}
+#endif
+
+int
+main ()
+{
+#if __BITINT_MAXWIDTH__ >= 129
+  if (!foo (90, 0x80000000000000000000000000000000uwb))
+    __builtin_abort ();
+#endif
+}