diff --git a/toolchain/check/handle_array.cpp b/toolchain/check/handle_array.cpp
index c1d9f815139e..25dd3f1cf548 100644
--- a/toolchain/check/handle_array.cpp
+++ b/toolchain/check/handle_array.cpp
@@ -37,7 +37,7 @@ auto HandleArrayExpression(Context& context, Parse::Node parse_node) -> bool {
   if (bound_node.kind() == SemIR::NodeKind::IntegerLiteral) {
     auto bound_value = context.semantics_ir().GetIntegerLiteral(
         bound_node.GetAsIntegerLiteral());
-    if (!bound_value.isNegative()) {
+    if (!bound_value.isNegative() && bound_value.getBitWidth() <= 64) {
       context.AddNodeAndPush(
           parse_node,
           SemIR::Node::ArrayType::Make(
diff --git a/toolchain/check/testdata/array/fail_bound_overflow.carbon b/toolchain/check/testdata/array/fail_bound_overflow.carbon
new file mode 100644
index 000000000000..17a9937548da
--- /dev/null
+++ b/toolchain/check/testdata/array/fail_bound_overflow.carbon
@@ -0,0 +1,48 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+
+// CHECK:STDERR: fail_bound_overflow.carbon:[[@LINE+3]]:32: Invalid array expression.
+// CHECK:STDERR: var a: [1; 39999999999999999993];
+// CHECK:STDERR:                                ^
+var a: [1; 39999999999999999993];
+
+// CHECK:STDOUT: cross_reference_irs_size: 1
+// CHECK:STDOUT: functions: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: integer_literals: [
+// CHECK:STDOUT:   1,
+// CHECK:STDOUT:   39999999999999999993,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: real_literals: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: strings: [
+// CHECK:STDOUT:   a,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: types: [
+// CHECK:STDOUT:   nodeIntegerType,
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: type_blocks: [
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: nodes: [
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int0, type: type0},
+// CHECK:STDOUT:   {kind: IntegerLiteral, arg0: int1, type: type0},
+// CHECK:STDOUT:   {kind: VarStorage, arg0: str0, type: typeError},
+// CHECK:STDOUT: ]
+// CHECK:STDOUT: node_blocks: [
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT:   [
+// CHECK:STDOUT:     node+0,
+// CHECK:STDOUT:     node+1,
+// CHECK:STDOUT:     node+2,
+// CHECK:STDOUT:   ],
+// CHECK:STDOUT: ]
+// CHECK:STDOUT:
+// CHECK:STDOUT: package {
+// CHECK:STDOUT:   %.loc10_9: i32 = int_literal 1
+// CHECK:STDOUT:   %.loc10_12: i32 = int_literal 39999999999999999993
+// CHECK:STDOUT:   %a: ref <error> = var "a"
+// CHECK:STDOUT: }