diff --git a/src/wgvk.c b/src/wgvk.c
index 1606866..58d0625 100644
--- a/src/wgvk.c
+++ b/src/wgvk.c
@@ -5691,6 +5691,46 @@ static inline VkColorSpaceKHR toVulkanColorSpace(WGPUPredefinedColorSpace wcsp,
 
 WGPUStatus wgpuSurfaceGetCapabilities(WGPUSurface wgpuSurface, WGPUAdapter adapter, WGPUSurfaceCapabilities* capabilities){
     ENTRY();
+    if(capabilities){
+        memset(capabilities, 0, sizeof(*capabilities));
+    }
+    if(wgpuSurface == NULL){
+        TRACELOG(WGPU_LOG_ERROR, "wgpuSurfaceGetCapabilities: surface is NULL");
+        EXIT();
+        return WGPUStatus_Error;
+    }
+    if(adapter == NULL){
+        TRACELOG(WGPU_LOG_ERROR, "wgpuSurfaceGetCapabilities: adapter is NULL");
+        if(wgpuSurface->device){
+            DeviceCallback(wgpuSurface->device, WGPUErrorType_Validation, STRVIEW("wgpuSurfaceGetCapabilities: adapter is NULL"));
+        }
+        EXIT();
+        return WGPUStatus_Error;
+    }
+    if(capabilities == NULL){
+        TRACELOG(WGPU_LOG_ERROR, "wgpuSurfaceGetCapabilities: capabilities is NULL");
+        if(wgpuSurface->device){
+            DeviceCallback(wgpuSurface->device, WGPUErrorType_Validation, STRVIEW("wgpuSurfaceGetCapabilities: capabilities is NULL"));
+        }
+        EXIT();
+        return WGPUStatus_Error;
+    }
+    if(wgpuSurface->surface == VK_NULL_HANDLE){
+        TRACELOG(WGPU_LOG_ERROR, "wgpuSurfaceGetCapabilities: surface handle is NULL");
+        if(wgpuSurface->device){
+            DeviceCallback(wgpuSurface->device, WGPUErrorType_Validation, STRVIEW("wgpuSurfaceGetCapabilities: surface is invalid"));
+        }
+        EXIT();
+        return WGPUStatus_Error;
+    }
+    if(adapter->physicalDevice == VK_NULL_HANDLE){
+        TRACELOG(WGPU_LOG_ERROR, "wgpuSurfaceGetCapabilities: adapter physical device is NULL");
+        if(wgpuSurface->device){
+            DeviceCallback(wgpuSurface->device, WGPUErrorType_Validation, STRVIEW("wgpuSurfaceGetCapabilities: adapter is invalid"));
+        }
+        EXIT();
+        return WGPUStatus_Error;
+    }
     if(wgpuSurface->capabilityCache.formatCount){
         *capabilities = wgpuSurface->capabilityCache;
         return WGPUStatus_Success;
diff --git a/tests/wgvk_unit_tests.cpp b/tests/wgvk_unit_tests.cpp
index e43cb9a..621a173 100644
--- a/tests/wgvk_unit_tests.cpp
+++ b/tests/wgvk_unit_tests.cpp
@@ -123,6 +123,22 @@ class WebGPUTest : public ::testing::Test {
     }
 };
 
+TEST(WGPUApiValidation, SurfaceGetCapabilitiesRejectsNullArgsAndClearsOutput) {
+    WGPUSurfaceCapabilities caps = {};
+    caps.formatCount = 123;
+    caps.presentModeCount = 456;
+    caps.alphaModeCount = 789;
+    caps.formats = reinterpret_cast<WGPUTextureFormat*>(uintptr_t(0x1));
+
+    EXPECT_EQ(wgpuSurfaceGetCapabilities(nullptr, nullptr, &caps), WGPUStatus_Error);
+    EXPECT_EQ(caps.formatCount, 0u);
+    EXPECT_EQ(caps.presentModeCount, 0u);
+    EXPECT_EQ(caps.alphaModeCount, 0u);
+    EXPECT_EQ(caps.formats, nullptr);
+
+    EXPECT_EQ(wgpuSurfaceGetCapabilities(nullptr, nullptr, nullptr), WGPUStatus_Error);
+}
+
 TEST_F(WebGPUTest, BufferReferenceCounting) {
     WGPUBufferDescriptor desc = {};
     desc.size = 1024;