diff --git a/dlls/setupapi/diskspace.c b/dlls/setupapi/diskspace.c
index 07025bd5a90..61e20dec015 100644
--- a/dlls/setupapi/diskspace.c
+++ b/dlls/setupapi/diskspace.c
@@ -53,6 +53,14 @@ HDSKSPC WINAPI SetupCreateDiskSpaceListW(PVOID Reserved1, DWORD Reserved2, UINT
     WCHAR *ptr;
     LPDISKSPACELIST list=NULL;
 
+    TRACE("(%p, %u, 0x%08x)\n", Reserved1, Reserved2, Flags);
+
+    if (Reserved1 || Reserved2 || Flags & ~SPDSL_IGNORE_DISK)
+    {
+        SetLastError(ERROR_INVALID_PARAMETER);
+        return NULL;
+    }
+
     rc = GetLogicalDriveStringsW(255,drives);
 
     if (rc == 0)
diff --git a/dlls/setupapi/tests/Makefile.in b/dlls/setupapi/tests/Makefile.in
index 27de9ff6954..2818ec0a982 100644
--- a/dlls/setupapi/tests/Makefile.in
+++ b/dlls/setupapi/tests/Makefile.in
@@ -7,6 +7,7 @@ IMPORTS   = setupapi user32 advapi32
 
 C_SRCS = \
 	devinst.c \
+	diskspace.c \
 	install.c \
 	misc.c \
 	parser.c \
diff --git a/dlls/setupapi/tests/diskspace.c b/dlls/setupapi/tests/diskspace.c
new file mode 100644
index 00000000000..33ea608d502
--- /dev/null
+++ b/dlls/setupapi/tests/diskspace.c
@@ -0,0 +1,153 @@
+/*
+ * Unit tests for disk space functions
+ *
+ * Copyright 2010 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
+ */
+
+#include <stdarg.h>
+
+#include "windef.h"
+#include "winbase.h"
+#include "winnls.h"
+#include "winuser.h"
+#include "winreg.h"
+#include "setupapi.h"
+
+#include "wine/test.h"
+
+static void test_SetupCreateDiskSpaceListA(void)
+{
+    HDSKSPC ret;
+
+    ret = SetupCreateDiskSpaceListA(NULL, 0, 0);
+    ok(ret != NULL,
+       "Expected SetupCreateDiskSpaceListA to return a valid handle, got NULL\n");
+
+    ok(SetupDestroyDiskSpaceList(ret), "Expected SetupDestroyDiskSpaceList to succeed\n");
+
+    ret = SetupCreateDiskSpaceListA(NULL, 0, SPDSL_IGNORE_DISK);
+    ok(ret != NULL,
+       "Expected SetupCreateDiskSpaceListA to return a valid handle, got NULL\n");
+
+    ok(SetupDestroyDiskSpaceList(ret), "Expected SetupDestroyDiskSpaceList to succeed\n");
+
+    SetLastError(0xdeadbeef);
+    ret = SetupCreateDiskSpaceListA(NULL, 0, ~0U);
+    ok(ret == NULL ||
+       broken(ret != NULL), /* NT4/Win9x/Win2k */
+       "Expected SetupCreateDiskSpaceListA to return NULL, got %p\n", ret);
+    if (!ret)
+        ok(GetLastError() == ERROR_INVALID_PARAMETER,
+           "Expected GetLastError() to return ERROR_INVALID_PARAMETER, got %u\n",
+           GetLastError());
+    else
+        ok(SetupDestroyDiskSpaceList(ret), "Expected SetupDestroyDiskSpaceList to succeed\n");
+
+    SetLastError(0xdeadbeef);
+    ret = SetupCreateDiskSpaceListA(NULL, 0xdeadbeef, 0);
+    ok(ret == NULL,
+       "Expected SetupCreateDiskSpaceListA to return NULL, got %p\n", ret);
+    ok(GetLastError() == ERROR_INVALID_PARAMETER ||
+       broken(GetLastError() == 0xdeadbeef), /* NT4/Win9x/Win2k */
+       "Expected GetLastError() to return ERROR_INVALID_PARAMETER, got %u\n",
+       GetLastError());
+
+    SetLastError(0xdeadbeef);
+    ret = SetupCreateDiskSpaceListA((void *)0xdeadbeef, 0, 0);
+    ok(ret == NULL,
+       "Expected SetupCreateDiskSpaceListA to return NULL, got %p\n", ret);
+    ok(GetLastError() == ERROR_INVALID_PARAMETER ||
+       broken(GetLastError() == 0xdeadbeef), /* NT4/Win9x/Win2k */
+       "Expected GetLastError() to return ERROR_INVALID_PARAMETER, got %u\n",
+       GetLastError());
+
+    SetLastError(0xdeadbeef);
+    ret = SetupCreateDiskSpaceListA((void *)0xdeadbeef, 0xdeadbeef, 0);
+    ok(ret == NULL,
+       "Expected SetupCreateDiskSpaceListA to return NULL, got %p\n", ret);
+    ok(GetLastError() == ERROR_INVALID_PARAMETER ||
+       broken(GetLastError() == 0xdeadbeef), /* NT4/Win9x/Win2k */
+       "Expected GetLastError() to return ERROR_INVALID_PARAMETER, got %u\n",
+       GetLastError());
+}
+
+static void test_SetupCreateDiskSpaceListW(void)
+{
+    HDSKSPC ret;
+
+    ret = SetupCreateDiskSpaceListW(NULL, 0, 0);
+    if (!ret && GetLastError() == ERROR_CALL_NOT_IMPLEMENTED)
+    {
+        win_skip("SetupCreateDiskSpaceListW is not implemented\n");
+        return;
+    }
+    ok(ret != NULL,
+       "Expected SetupCreateDiskSpaceListW to return a valid handle, got NULL\n");
+
+    ok(SetupDestroyDiskSpaceList(ret), "Expected SetupDestroyDiskSpaceList to succeed\n");
+
+    ret = SetupCreateDiskSpaceListW(NULL, 0, SPDSL_IGNORE_DISK);
+    ok(ret != NULL,
+       "Expected SetupCreateDiskSpaceListW to return a valid handle, got NULL\n");
+
+    ok(SetupDestroyDiskSpaceList(ret), "Expected SetupDestroyDiskSpaceList to succeed\n");
+
+    SetLastError(0xdeadbeef);
+    ret = SetupCreateDiskSpaceListW(NULL, 0, ~0U);
+    ok(ret == NULL ||
+       broken(ret != NULL), /* NT4/Win2k */
+       "Expected SetupCreateDiskSpaceListW to return NULL, got %p\n", ret);
+    if (!ret)
+        ok(GetLastError() == ERROR_INVALID_PARAMETER,
+           "Expected GetLastError() to return ERROR_INVALID_PARAMETER, got %u\n",
+           GetLastError());
+    else
+        ok(SetupDestroyDiskSpaceList(ret), "Expected SetupDestroyDiskSpaceList to succeed\n");
+
+    SetLastError(0xdeadbeef);
+    ret = SetupCreateDiskSpaceListW(NULL, 0xdeadbeef, 0);
+    ok(ret == NULL,
+       "Expected SetupCreateDiskSpaceListW to return NULL, got %p\n", ret);
+    ok(GetLastError() == ERROR_INVALID_PARAMETER ||
+       broken(GetLastError() == 0xdeadbeef), /* NT4/Win2k */
+       "Expected GetLastError() to return ERROR_INVALID_PARAMETER, got %u\n",
+       GetLastError());
+
+    SetLastError(0xdeadbeef);
+    ret = SetupCreateDiskSpaceListW((void *)0xdeadbeef, 0, 0);
+    ok(ret == NULL,
+       "Expected SetupCreateDiskSpaceListW to return NULL, got %p\n", ret);
+    ok(GetLastError() == ERROR_INVALID_PARAMETER ||
+       broken(GetLastError() == 0xdeadbeef), /* NT4/Win2k */
+       "Expected GetLastError() to return ERROR_INVALID_PARAMETER, got %u\n",
+       GetLastError());
+
+    SetLastError(0xdeadbeef);
+    ret = SetupCreateDiskSpaceListW((void *)0xdeadbeef, 0xdeadbeef, 0);
+    ok(ret == NULL,
+       "Expected SetupCreateDiskSpaceListW to return NULL, got %p\n", ret);
+    ok(GetLastError() == ERROR_INVALID_PARAMETER ||
+       broken(GetLastError() == 0xdeadbeef), /* NT4/Win2k */
+       "Expected GetLastError() to return ERROR_INVALID_PARAMETER, got %u\n",
+       GetLastError());
+}
+
+START_TEST(diskspace)
+{
+    test_SetupCreateDiskSpaceListA();
+    test_SetupCreateDiskSpaceListW();
+}