diff --git a/src/compiler/representation-change.cc b/src/compiler/representation-change.cc
index 99b3d644ab..9478e1510e 100644
--- a/src/compiler/representation-change.cc
+++ b/src/compiler/representation-change.cc
@@ -175,6 +175,15 @@ Node* RepresentationChanger::GetRepresentationFor(
     }
   }
 
+  // Rematerialize any truncated BigInt if user is not expecting a BigInt.
+  if (output_type.Is(Type::BigInt()) &&
+      output_rep == MachineRepresentation::kWord64 &&
+      use_info.type_check() != TypeCheckKind::kBigInt) {
+    node =
+        InsertConversion(node, simplified()->ChangeUint64ToBigInt(), use_node);
+    output_rep = MachineRepresentation::kTaggedPointer;
+  }
+
   switch (use_info.representation()) {
     case MachineRepresentation::kTaggedSigned:
       DCHECK(use_info.type_check() == TypeCheckKind::kNone ||
diff --git a/test/mjsunit/regress/regress-1029530.js b/test/mjsunit/regress/regress-1029530.js
new file mode 100644
index 0000000000..918a9ecbb4
--- /dev/null
+++ b/test/mjsunit/regress/regress-1029530.js
@@ -0,0 +1,40 @@
+// Copyright 2019 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --interrupt-budget=1024
+
+{
+  function f() {
+    const b = BigInt.asUintN(4,3n);
+    let i = 0;
+    while(i < 1) {
+      i + 1;
+      i = b;
+    }
+  }
+
+  %PrepareFunctionForOptimization(f);
+  f();
+  f();
+  %OptimizeFunctionOnNextCall(f);
+  f();
+}
+
+
+{
+  function f() {
+    const b = BigInt.asUintN(4,10n);
+    let i = 0.1;
+    while(i < 1.8) {
+      i + 1;
+      i = b;
+    }
+  }
+
+  %PrepareFunctionForOptimization(f);
+  f();
+  f();
+  %OptimizeFunctionOnNextCall(f);
+  f();
+}