diff --git a/configure b/configure
index 6484f8b5871..73d6b77d5e7 100755
--- a/configure
+++ b/configure
@@ -14840,6 +14840,14 @@ ALL_MAKEFILE_DEPENDS="$ALL_MAKEFILE_DEPENDS
 dlls/dxdiagn/Makefile: dlls/dxdiagn/Makefile.in dlls/Makedll.rules"
 ac_config_files="$ac_config_files dlls/dxdiagn/Makefile"
 
+ALL_MAKEFILES="$ALL_MAKEFILES \\
+	dlls/dxdiagn/tests/Makefile"
+test "x$enable_tests" != xno && ALL_TEST_DIRS="$ALL_TEST_DIRS \\
+	dxdiagn/tests"
+ALL_MAKEFILE_DEPENDS="$ALL_MAKEFILE_DEPENDS
+dlls/dxdiagn/tests/Makefile: dlls/dxdiagn/tests/Makefile.in dlls/Maketest.rules"
+ac_config_files="$ac_config_files dlls/dxdiagn/tests/Makefile"
+
 ALL_MAKEFILES="$ALL_MAKEFILES \\
 	dlls/dxerr8/Makefile"
 test "x$enable_dxerr8" != xno && ALL_IMPLIB_DIRS="$ALL_IMPLIB_DIRS \\
@@ -19001,6 +19009,7 @@ do
     "dlls/dswave/Makefile") CONFIG_FILES="$CONFIG_FILES dlls/dswave/Makefile" ;;
     "dlls/dwmapi/Makefile") CONFIG_FILES="$CONFIG_FILES dlls/dwmapi/Makefile" ;;
     "dlls/dxdiagn/Makefile") CONFIG_FILES="$CONFIG_FILES dlls/dxdiagn/Makefile" ;;
+    "dlls/dxdiagn/tests/Makefile") CONFIG_FILES="$CONFIG_FILES dlls/dxdiagn/tests/Makefile" ;;
     "dlls/dxerr8/Makefile") CONFIG_FILES="$CONFIG_FILES dlls/dxerr8/Makefile" ;;
     "dlls/dxerr9/Makefile") CONFIG_FILES="$CONFIG_FILES dlls/dxerr9/Makefile" ;;
     "dlls/dxgi/Makefile") CONFIG_FILES="$CONFIG_FILES dlls/dxgi/Makefile" ;;
diff --git a/configure.ac b/configure.ac
index 99fb6b9040a..62ea51f69d2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2240,6 +2240,7 @@ WINE_CONFIG_MAKEFILE([dlls/dssenh/Makefile],[dlls/Makedll.rules],[dlls],[ALL_DLL
 WINE_CONFIG_MAKEFILE([dlls/dswave/Makefile],[dlls/Makedll.rules],[dlls],[ALL_DLL_DIRS])
 WINE_CONFIG_MAKEFILE([dlls/dwmapi/Makefile],[dlls/Makedll.rules],[dlls],[ALL_DLL_DIRS])
 WINE_CONFIG_MAKEFILE([dlls/dxdiagn/Makefile],[dlls/Makedll.rules],[dlls],[ALL_DLL_DIRS])
+WINE_CONFIG_MAKEFILE([dlls/dxdiagn/tests/Makefile],[dlls/Maketest.rules],[dlls],[ALL_TEST_DIRS],[enable_tests])
 WINE_CONFIG_MAKEFILE([dlls/dxerr8/Makefile],[dlls/Makeimplib.rules],[dlls],[ALL_IMPLIB_DIRS])
 WINE_CONFIG_MAKEFILE([dlls/dxerr9/Makefile],[dlls/Makeimplib.rules],[dlls],[ALL_IMPLIB_DIRS])
 WINE_CONFIG_MAKEFILE([dlls/dxgi/Makefile],[dlls/Makedll.rules],[dlls],[ALL_DLL_DIRS])
diff --git a/dlls/dxdiagn/tests/Makefile.in b/dlls/dxdiagn/tests/Makefile.in
new file mode 100644
index 00000000000..720e38269b5
--- /dev/null
+++ b/dlls/dxdiagn/tests/Makefile.in
@@ -0,0 +1,13 @@
+TOPSRCDIR = @top_srcdir@
+TOPOBJDIR = ../../..
+SRCDIR    = @srcdir@
+VPATH     = @srcdir@
+TESTDLL   = dxdiagn.dll
+IMPORTS   = ole32 kernel32
+
+CTESTS = \
+	provider.c
+
+@MAKE_TEST_RULES@
+
+@DEPENDENCIES@  # everything below this line is overwritten by make depend
diff --git a/dlls/dxdiagn/tests/provider.c b/dlls/dxdiagn/tests/provider.c
new file mode 100644
index 00000000000..a893842221d
--- /dev/null
+++ b/dlls/dxdiagn/tests/provider.c
@@ -0,0 +1,152 @@
+/*
+ * Unit tests for IDxDiagProvider
+ *
+ * Copyright (C) 2009 Andrew Nguyen
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#define COBJMACROS
+
+#include "initguid.h"
+#include "dxdiag.h"
+#include "wine/test.h"
+
+static void test_Initialize(void)
+{
+    HRESULT hr;
+    IDxDiagProvider *pddp;
+    DXDIAG_INIT_PARAMS params;
+
+    hr = CoCreateInstance(&CLSID_DxDiagProvider, NULL, CLSCTX_INPROC_SERVER,
+                          &IID_IDxDiagProvider, (LPVOID*)&pddp);
+    ok(hr == S_OK, "Creating a IDxDiagProvider instance failed with %x\n", hr);
+    if (FAILED(hr))
+    {
+        skip("Failed to create a IDxDiagProvider instance\n");
+        return;
+    }
+
+    /* Test passing a NULL DXDIAG_INIT_PARAMS pointer. */
+    hr = IDxDiagProvider_Initialize(pddp, NULL);
+    ok(hr == E_POINTER,
+       "Expected IDxDiagProvider::Initialize to return E_POINTER, got %x\n", hr);
+
+    /* Test passing invalid dwSize values. */
+    params.dwSize = 0;
+    hr = IDxDiagProvider_Initialize(pddp, &params);
+    ok(hr == E_INVALIDARG,
+       "Expected IDxDiagProvider::Initialize to return E_INVALIDARG, got %x\n", hr);
+
+    params.dwSize = sizeof(params) + 1;
+    hr = IDxDiagProvider_Initialize(pddp, &params);
+    ok(hr == E_INVALIDARG,
+       "Expected IDxDiagProvider::Initialize to return E_INVALIDARG, got %x\n", hr);
+
+    /* Test passing an unexpected dwDxDiagHeaderVersion value. */
+    params.dwSize = sizeof(params);
+    params.dwDxDiagHeaderVersion = 0;
+    params.bAllowWHQLChecks = FALSE;
+    params.pReserved = NULL;
+    hr = IDxDiagProvider_Initialize(pddp, &params);
+    todo_wine
+    ok(hr == E_INVALIDARG,
+       "Expected IDxDiagProvider::Initialize to return E_INVALIDARG, got %x\n", hr);
+
+    /* Setting pReserved to a non-NULL value causes a crash on Windows. */
+    if (0)
+    {
+        params.dwDxDiagHeaderVersion = DXDIAG_DX9_SDK_VERSION;
+        params.bAllowWHQLChecks = FALSE;
+        params.pReserved = (VOID*)0xdeadbeef;
+        hr = IDxDiagProvider_Initialize(pddp, &params);
+        trace("IDxDiagProvider::Initialize returned %x\n", hr);
+    }
+
+    /* Test passing an appropriately initialized DXDIAG_INIT_PARAMS. */
+    params.dwDxDiagHeaderVersion = DXDIAG_DX9_SDK_VERSION;
+    params.bAllowWHQLChecks = FALSE;
+    params.pReserved = NULL;
+    hr = IDxDiagProvider_Initialize(pddp, &params);
+    ok(hr == S_OK, "Expected IDxDiagProvider::Initialize to return S_OK, got %x\n", hr);
+
+    /* Test initializing multiple times. */
+    hr = IDxDiagProvider_Initialize(pddp, &params);
+    ok(hr == S_OK, "Expected IDxDiagProvider::Initialize to return S_OK, got %x\n", hr);
+
+    IDxDiagProvider_Release(pddp);
+}
+
+static void test_GetRootContainer(void)
+{
+    HRESULT hr;
+    IDxDiagProvider *pddp;
+    IDxDiagContainer *pddc;
+    DXDIAG_INIT_PARAMS params;
+
+    hr = CoCreateInstance(&CLSID_DxDiagProvider, NULL, CLSCTX_INPROC_SERVER,
+                          &IID_IDxDiagProvider, (LPVOID*)&pddp);
+    ok(hr == S_OK, "Creating a IDxDiagProvider instance failed with %x\n", hr);
+    if (FAILED(hr))
+    {
+        skip("Failed to create a IDxDiagProvider instance\n");
+        return;
+    }
+
+    /* Test calling IDxDiagProvider::GetRootContainer before initialization. */
+    hr = IDxDiagProvider_GetRootContainer(pddp, NULL);
+    todo_wine
+    ok(hr == CO_E_NOTINITIALIZED,
+       "Expected IDxDiagProvider::GetRootContainer to return CO_E_NOTINITIALIZED, got %x\n", hr);
+
+    hr = IDxDiagProvider_GetRootContainer(pddp, &pddc);
+    todo_wine
+    ok(hr == CO_E_NOTINITIALIZED,
+       "Expected IDxDiagProvider::GetRootContainer to return CO_E_NOTINITIALIZED, got %x\n", hr);
+
+    params.dwSize = sizeof(params);
+    params.dwDxDiagHeaderVersion = DXDIAG_DX9_SDK_VERSION;
+    params.bAllowWHQLChecks = FALSE;
+    params.pReserved = NULL;
+    hr = IDxDiagProvider_Initialize(pddp, &params);
+    ok(hr == S_OK, "Expected IDxDiagProvider::Initialize to return S_OK, got %x\n", hr);
+    if (FAILED(hr))
+    {
+        skip("IDxDiagProvider::Initialize failed\n");
+        IDxDiagProvider_Release(pddp);
+        return;
+    }
+
+    /* Passing NULL causes a crash on Windows. */
+    if (0)
+    {
+        hr = IDxDiagProvider_GetRootContainer(pddp, NULL);
+        trace("IDxDiagProvider::GetRootContainer returned %x\n", hr);
+    }
+
+    hr = IDxDiagProvider_GetRootContainer(pddp, &pddc);
+    ok(hr == S_OK, "Expected IDxDiagProvider::GetRootContainer to return S_OK, got %x\n", hr);
+
+    IDxDiagContainer_Release(pddc);
+    IDxDiagProvider_Release(pddp);
+}
+
+START_TEST(provider)
+{
+    CoInitialize(NULL);
+    test_Initialize();
+    test_GetRootContainer();
+    CoUninitialize();
+}