diff --git a/packages/nitrogen/src/index.ts b/packages/nitrogen/src/index.ts
index 8a79106db..f10681394 100644
--- a/packages/nitrogen/src/index.ts
+++ b/packages/nitrogen/src/index.ts
@@ -24,7 +24,13 @@ let generatedSpecs = 0
 const baseDirectory = getBaseDirectory()
 
 // The TS project
-const project = new Project({})
+const project = new Project({
+  compilerOptions: {
+    strict: true,
+    strictNullChecks: true,
+    noUncheckedIndexedAccess: true,
+  },
+})
 project.addSourceFilesAtPaths(path.join(baseDirectory, '/**/*.nitro.ts'))
 
 // Loop through all source files to log them
diff --git a/packages/nitrogen/src/syntax/Method.ts b/packages/nitrogen/src/syntax/Method.ts
index f11de61f8..9980a468c 100644
--- a/packages/nitrogen/src/syntax/Method.ts
+++ b/packages/nitrogen/src/syntax/Method.ts
@@ -59,8 +59,7 @@ export class Method implements CodeNode {
       const [method] = args
       this.name = method.getSymbolOrThrow().getEscapedName()
       const returnType = method.getReturnType()
-      const isOptional = returnType.isNullable()
-      this.returnType = createType(returnType, isOptional)
+      this.returnType = createType(returnType, returnType.isNullable())
       this.parameters = method.getParameters().map((p) => new Parameter(p))
     }
   }
diff --git a/packages/nitrogen/src/syntax/createType.ts b/packages/nitrogen/src/syntax/createType.ts
index 8baff846d..eac2810e1 100644
--- a/packages/nitrogen/src/syntax/createType.ts
+++ b/packages/nitrogen/src/syntax/createType.ts
@@ -176,14 +176,17 @@ export function createType(type: TSMorphType, isOptional: boolean): Type {
       return new EnumType(typename, type)
     } else {
       // It consists of different types - that means it's a variant!
-      const variants = type.getUnionTypes().map((t) => createType(t, false))
-      const isOptionalVariant = variants.some((t) => t.kind === 'null')
-      const variant = new VariantType(variants.filter((v) => v.kind !== 'null'))
-      if (isOptionalVariant) {
-        return new OptionalType(variant)
-      } else {
-        return variant
+      const variants = type
+        .getUnionTypes()
+        // Filter out any nulls or undefineds, as those are already treated as `isOptional`.
+        .filter((t) => !t.isNull() && !t.isUndefined() && !t.isVoid())
+        .map((t) => createType(t, false))
+      if (variants.length === 1) {
+        // It's just one type with undefined/null varians - so we treat it like a simple optional.
+        return variants[0]!
       }
+
+      return new VariantType(variants)
     }
   } else if (type.isInterface()) {
     // It references another interface/type, either a simple struct, or another HybridObject
diff --git a/packages/react-native-nitro-image/nitrogen/generated/shared/c++/HybridTestObjectSpec.hpp b/packages/react-native-nitro-image/nitrogen/generated/shared/c++/HybridTestObjectSpec.hpp
index 3946b4201..da513feb9 100644
--- a/packages/react-native-nitro-image/nitrogen/generated/shared/c++/HybridTestObjectSpec.hpp
+++ b/packages/react-native-nitro-image/nitrogen/generated/shared/c++/HybridTestObjectSpec.hpp
@@ -67,10 +67,10 @@ namespace margelo::nitro::image {
       virtual void setStringValue(const std::string& stringValue) = 0;
       virtual int64_t getBigintValue() = 0;
       virtual void setBigintValue(int64_t bigintValue) = 0;
-      virtual std::string getStringOrUndefined() = 0;
-      virtual void setStringOrUndefined(const std::string& stringOrUndefined) = 0;
-      virtual std::string getStringOrNull() = 0;
-      virtual void setStringOrNull(const std::string& stringOrNull) = 0;
+      virtual std::optional<std::string> getStringOrUndefined() = 0;
+      virtual void setStringOrUndefined(const std::optional<std::string>& stringOrUndefined) = 0;
+      virtual std::optional<std::string> getStringOrNull() = 0;
+      virtual void setStringOrNull(const std::optional<std::string>& stringOrNull) = 0;
       virtual std::optional<std::string> getOptionalString() = 0;
       virtual void setOptionalString(const std::optional<std::string>& optionalString) = 0;
       virtual double getValueThatWillThrowOnAccess() = 0;
@@ -89,7 +89,7 @@ namespace margelo::nitro::image {
       virtual std::shared_ptr<AnyMap> mapRoundtrip(const std::shared_ptr<AnyMap>& map) = 0;
       virtual double funcThatThrows() = 0;
       virtual std::string tryOptionalParams(double num, bool boo, const std::optional<std::string>& str) = 0;
-      virtual std::string tryMiddleParam(double num, bool boo, const std::string& str) = 0;
+      virtual std::string tryMiddleParam(double num, const std::optional<std::variant<bool>>& boo, const std::string& str) = 0;
       virtual std::variant<std::string, double> passVariant(const std::variant<std::string, double, bool, std::vector<double>, std::vector<std::string>>& either) = 0;
       virtual std::tuple<double, double, double> flip(const std::tuple<double, double, double>& tuple) = 0;
       virtual std::tuple<double, std::string, bool> passTuple(const std::tuple<double, std::string, bool>& tuple) = 0;
@@ -103,7 +103,7 @@ namespace margelo::nitro::image {
       virtual std::future<void> getValueFromJsCallback(const Func_std__future_std__string_& callback, const Func_void_std__string& andThenCall) = 0;
       virtual Car getCar() = 0;
       virtual bool isCarElectric(const Car& car) = 0;
-      virtual Person getDriver(const Car& car) = 0;
+      virtual std::optional<Person> getDriver(const Car& car) = 0;
       virtual std::shared_ptr<ArrayBuffer> createArrayBuffer() = 0;
       virtual double getBufferLastItem(const std::shared_ptr<ArrayBuffer>& buffer) = 0;
       virtual void setAllValuesTo(const std::shared_ptr<ArrayBuffer>& buffer, double value) = 0;