4 files changed, 7 insertions, 3 deletions
diff --git a/packages/json-schemas/CHANGELOG.json b/packages/json-schemas/CHANGELOG.json
index 5ed7cc6ee..81f8e3220 100644
--- a/packages/json-schemas/CHANGELOG.json
+++ b/packages/json-schemas/CHANGELOG.json
@@ -5,6 +5,10 @@
             {
                 "note": "Allow for additional properties in txData schema",
                 "pr": 938
+            },
+            {
+                "note": "Change hexSchema to match `0x`",
+                "pr": 937
             }
         ]
     },
diff --git a/packages/json-schemas/package.json b/packages/json-schemas/package.json
index 4793fc0d5..6f0376d1b 100644
--- a/packages/json-schemas/package.json
+++ b/packages/json-schemas/package.json
@@ -70,7 +70,7 @@
         "shx": "^0.2.2",
         "tslint": "5.11.0",
         "typedoc": "0xProject/typedoc",
-        "typescript": "2.7.1"
+        "typescript": "2.9.2"
     },
     "publishConfig": {
         "access": "public"
diff --git a/packages/json-schemas/schemas/basic_type_schemas.ts b/packages/json-schemas/schemas/basic_type_schemas.ts
index 7565df9e0..301f9ec73 100644
--- a/packages/json-schemas/schemas/basic_type_schemas.ts
+++ b/packages/json-schemas/schemas/basic_type_schemas.ts
@@ -7,7 +7,7 @@ export const addressSchema = {
 export const hexSchema = {
     id: '/Hex',
     type: 'string',
-    pattern: '^0x([0-9a-f][0-9a-f])+$',
+    pattern: '^0x(([0-9a-f][0-9a-f])+)?$',
 };
 
 export const numberSchema = {
diff --git a/packages/json-schemas/test/schema_test.ts b/packages/json-schemas/test/schema_test.ts
index d202b5643..f84553df1 100644
--- a/packages/json-schemas/test/schema_test.ts
+++ b/packages/json-schemas/test/schema_test.ts
@@ -89,7 +89,7 @@ describe('Schema', () => {
             validateAgainstSchema(testCases, hexSchema);
         });
         it('should fail for invalid hex string', () => {
-            const testCases = ['0x', '0', '0xzzzzzzB11a196601eD2ce54B665CaFEca0347D42'];
+            const testCases = ['0', '0xzzzzzzB11a196601eD2ce54B665CaFEca0347D42'];
             const shouldFail = true;
             validateAgainstSchema(testCases, hexSchema, shouldFail);
         });