diff --git a/src/tinyusdz.cc b/src/tinyusdz.cc
index 329da318..1c186996 100644
--- a/src/tinyusdz.cc
+++ b/src/tinyusdz.cc
@@ -648,9 +648,10 @@ bool LoadUSDAFromMemory(const uint8_t *addr, const size_t length,
 
   tinyusdz::StreamReader sr(addr, length, /* swap endian */ false);
   tinyusdz::usda::USDAReader reader(&sr);
-  
+
   tinyusdz::usda::USDAReaderConfig config;
   config.strict_allowedToken_check = options.strict_allowedToken_check;
+  config.allow_unknown_apiSchema = !options.strict_apiSchema_check;
   reader.set_reader_config(config);
 
   reader.SetBaseDir(base_dir);
@@ -987,6 +988,7 @@ bool LoadUSDCLayerFromMemory(const uint8_t *addr, const size_t length,
   usdc::USDCReaderConfig config;
   config.numThreads = options.num_threads;
   config.strict_allowedToken_check = options.strict_allowedToken_check;
+  config.allow_unknown_apiSchemas = !options.strict_apiSchema_check;
   usdc::USDCReader reader(&sr, config);
 
   if (!reader.ReadUSDC()) {
@@ -1250,7 +1252,7 @@ int USDZResolveAsset(const char *asset_name, const std::vector<std::string> &sea
 
   std::string asset_path = asset_name;
 
-  // Remove relative path prefix './' 
+  // Remove relative path prefix './'
   if (tinyusdz::startsWith(asset_path, "./")) {
     asset_path = tinyusdz::removePrefix(asset_path, "./");
   }
@@ -1391,11 +1393,11 @@ bool SetupUSDZAssetResolution(
   // https://openusd.org/release/spec_usdz.html
   //
   // [x] Image: png, jpeg(jpg), exr
-  // 
+  //
   // TODO(LTE):
   //
-  // [ ] USD: usda, usdc, usd 
-  // [ ] Audio: m4a, mp3, wav 
+  // [ ] USD: usda, usdc, usd
+  // [ ] Audio: m4a, mp3, wav
 
   if (!pusdzAsset) {
     return false;
@@ -1406,9 +1408,9 @@ bool SetupUSDZAssetResolution(
   handler.resolve_fun = USDZResolveAsset;
   handler.size_fun = USDZSizeAsset;
   handler.read_fun = USDZReadAsset;
-  handler.write_fun = nullptr; 
+  handler.write_fun = nullptr;
   handler.userdata = reinterpret_cast<void *>(const_cast<USDZAsset *>(pusdzAsset));
- 
+
   resolver.register_asset_resolution_handler("png", handler);
   resolver.register_asset_resolution_handler("PNG", handler);
   resolver.register_asset_resolution_handler("JPG", handler);
@@ -1417,7 +1419,7 @@ bool SetupUSDZAssetResolution(
   resolver.register_asset_resolution_handler("JPEG", handler);
   resolver.register_asset_resolution_handler("exr", handler);
   resolver.register_asset_resolution_handler("EXR", handler);
-   
+
   return true;
 }
 
diff --git a/src/usda-reader.cc b/src/usda-reader.cc
index bc98e8d6..b2d6e302 100644
--- a/src/usda-reader.cc
+++ b/src/usda-reader.cc
@@ -1069,8 +1069,10 @@ class USDAReader::Impl {
               auto ret = ApiSchemaHandler(item.str());
               if (ret) {
                 apiSchemas.names.push_back({ret.value(), /* instanceName */""});
-              } else {
+              } else if (_config.allow_unknown_apiSchema) {
                 PUSH_WARN("(PrimMeta) " << ret.error());
+              } else {
+                PUSH_ERROR_AND_RETURN("Unknown or invalid apiSchema: " + ret.error());
               }
             }
           } else {
diff --git a/tests/usda/apishcema-002.usda b/tests/usda/apishcema-002.usda
new file mode 100644
index 00000000..0ca46331
--- /dev/null
+++ b/tests/usda/apishcema-002.usda
@@ -0,0 +1,16 @@
+#usda 1.0
+(
+    metersPerUnit = 1
+    upAxis = "Y"
+    defaultPrim = "hello"
+)
+
+def Cone "hello"
+(
+  # would report warning for HoudiniViewportGuideAPI
+  prepend apiSchemas = ["HoudiniViewportGuideAPI", "GeomModelAPI", "MotionAPI", "ListAPI", "LightListAPI"]
+)
+{
+  uniform token axis = "X"
+  double height = 1.2
+}
diff --git a/tests/usdc/apischema-002.usdc b/tests/usdc/apischema-002.usdc
new file mode 100644
index 00000000..bdb0fa7d
Binary files /dev/null and b/tests/usdc/apischema-002.usdc differ