diff --git a/.changeset/config.json b/.changeset/config.json
index 1c540ad6..a96e5bac 100644
--- a/.changeset/config.json
+++ b/.changeset/config.json
@@ -1,7 +1,7 @@
 {
-  "$schema": "https://unpkg.com/@changesets/config@0.2.4/schema.json",
+  "$schema": "https://unpkg.com/@changesets/config@1.0.0/schema.json",
   "changelog": "@changesets/cli/changelog",
   "commit": false,
-  "linked": [],
+  "linked": [["gqless", "@gqless/react"]],
   "access": "public"
 }
diff --git a/.changeset/nasty-zebras-count.md b/.changeset/nasty-zebras-count.md
new file mode 100644
index 00000000..c575f435
--- /dev/null
+++ b/.changeset/nasty-zebras-count.md
@@ -0,0 +1,5 @@
+---
+'@gqless/schema': patch
+---
+
+Fix input object nullability
diff --git a/.codesandbox/ci.json b/.codesandbox/ci.json
index 4d8f8196..ac815597 100644
--- a/.codesandbox/ci.json
+++ b/.codesandbox/ci.json
@@ -1,5 +1,5 @@
 {
-  "installCommand": "install",
+  "packages": ["gqless", "packages/react", "packages/logger", "packages/utils"],
   "buildCommand": "build",
   "sandboxes": ["/examples/react-hackernews"]
 }
diff --git a/codecov.yml b/codecov.yml
new file mode 100644
index 00000000..ba6f0b2b
--- /dev/null
+++ b/codecov.yml
@@ -0,0 +1,2 @@
+comment:
+  require_changes: true
diff --git a/packages/schema/src/Codegen/files/generated/types.ts b/packages/schema/src/Codegen/files/generated/types.ts
index 986520f0..e10b7f3a 100644
--- a/packages/schema/src/Codegen/files/generated/types.ts
+++ b/packages/schema/src/Codegen/files/generated/types.ts
@@ -221,11 +221,12 @@ export class TypesFile extends File {
   }
 
   public generateField(field: SchemaField, resolveType?: TypeResolver) {
+    const NULLABLE = field.type.nullable ? '?' : ''
     const fieldType = this.generateType(field.type, resolveType)
 
     if (field.args) this.import(CORE, this.names.FieldsTypeArg)
 
-    return `${this.generateFieldComments(field)}${field.name}: ${
+    return `${this.generateFieldComments(field)}${field.name}${NULLABLE}: ${
       field.args
         ? `${this.names.FieldsTypeArg}<${this.generateArgs(
             field.args