diff --git a/scripts/genesis/ProtocolConfig.ts b/scripts/genesis/ProtocolConfig.ts
index 6b52ce6b..7cf7933b 100644
--- a/scripts/genesis/ProtocolConfig.ts
+++ b/scripts/genesis/ProtocolConfig.ts
@@ -71,7 +71,7 @@ export const schemaProtocolConfig = z
       inverseElasticityMultiplier: schemaBigInt.min(0n).max(10000n),
       minBaseFee: schemaBigInt.min(0n).max(maxUint64),
       maxBaseFee: schemaBigInt.min(0n).max(maxUint64),
-      blockGasLimit: schemaBigInt.min(0n).max(maxUint64),
+      blockGasLimit: schemaBigInt.min(1n).max(maxUint64),
     }),
     consensusParams: z
       .object({
diff --git a/tests/unit/protocol-config-schema.test.ts b/tests/unit/protocol-config-schema.test.ts
new file mode 100644
index 00000000..9f470f0f
--- /dev/null
+++ b/tests/unit/protocol-config-schema.test.ts
@@ -0,0 +1,49 @@
+// Copyright 2026 Circle Internet Group, Inc. All rights reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { expect } from 'chai'
+import { schemaProtocolConfig } from '../../scripts/genesis/ProtocolConfig'
+
+const maxUint64 = 18446744073709551615n
+
+const configWithBlockGasLimit = (blockGasLimit: bigint) => ({
+  proxy: { admin: '0x0000000000000000000000000000000000000001' },
+  owner: '0x0000000000000000000000000000000000000002',
+  controller: '0x0000000000000000000000000000000000000003',
+  pauser: '0x0000000000000000000000000000000000000004',
+  feeParams: {
+    alpha: 0n,
+    kRate: 0n,
+    inverseElasticityMultiplier: 0n,
+    minBaseFee: 0n,
+    maxBaseFee: 0n,
+    blockGasLimit,
+  },
+})
+
+describe('schemaProtocolConfig', () => {
+  it('accepts the minimum positive block gas limit', () => {
+    expect(schemaProtocolConfig.safeParse(configWithBlockGasLimit(1n)).success).to.equal(true)
+  })
+
+  it('rejects a zero block gas limit', () => {
+    expect(schemaProtocolConfig.safeParse(configWithBlockGasLimit(0n)).success).to.equal(false)
+  })
+
+  it('rejects block gas limits above uint64', () => {
+    expect(schemaProtocolConfig.safeParse(configWithBlockGasLimit(maxUint64 + 1n)).success).to.equal(false)
+  })
+})