diff --git a/tests/Makefile.am b/tests/Makefile.am
index 0f417f7..7df10d0 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -172,6 +172,8 @@ endif # ENABLE_GLX
 TESTS_EGL =
 TESTS_EGL += testegldisplay.sh
 TESTS_EGL += testegldevice.sh
+TESTS_EGL += testegldeviceadd_querydevices.sh
+TESTS_EGL += testegldeviceadd_returndevice.sh
 TESTS_EGL += testeglgetprocaddress.sh
 TESTS_EGL += testeglmakecurrent.sh
 TESTS_EGL += testeglerror.sh
@@ -193,6 +195,12 @@ testegldevice_SOURCES = \
 	egl_test_utils.c
 testegldevice_LDADD = $(top_builddir)/src/EGL/libEGL.la @LIB_DL@
 
+check_PROGRAMS += testegldeviceadd
+testegldeviceadd_SOURCES = \
+	testegldeviceadd.c \
+	egl_test_utils.c
+testegldeviceadd_LDADD = $(top_builddir)/src/EGL/libEGL.la @LIB_DL@
+
 check_PROGRAMS += testeglgetprocaddress
 testeglgetprocaddress_SOURCES = \
 	testeglgetprocaddress.c \
diff --git a/tests/meson.build b/tests/meson.build
index 2173b48..8be6cf3 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -215,5 +215,22 @@ if get_option('egl')
       depends : libEGL_dummy,
     )
   endforeach
+
+  exe_egldeviceadd = executable(
+    'egldeviceadd',
+    ['testegldeviceadd.c', 'egl_test_utils.c'],
+    include_directories : [inc_include],
+    link_with : [libEGL],
+    dependencies : [dep_dl],
+  )
+  foreach t : [ 'querydevices', 'returndevice' ]
+    test(
+      'egldeviceadd (@0@)'.format(t),
+      exe_egldeviceadd,
+      args : [t],
+      env : env_egl,
+      suite : ['egl'],
+    )
+  endforeach
 endif
 
diff --git a/tests/testegldeviceadd.c b/tests/testegldeviceadd.c
new file mode 100644
index 0000000..3c10e31
--- /dev/null
+++ b/tests/testegldeviceadd.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and/or associated documentation files (the
+ * "Materials"), to deal in the Materials without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Materials, and to
+ * permit persons to whom the Materials are furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * unaltered in all copies or substantial portions of the Materials.
+ * Any additions, deletions, or changes to the original source files
+ * must be clearly indicated in accompanying documentation.
+ *
+ * If only executable code is distributed, then the accompanying
+ * documentation must state that "this software is based in part on the
+ * work of the Khronos Group."
+ *
+ * THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+ */
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "dummy/EGL_dummy.h"
+#include "egl_test_utils.h"
+
+#define DEVICE_ARRAY_SIZE (DUMMY_EGL_MAX_DEVICE_COUNT * DUMMY_VENDOR_COUNT)
+
+EGLBoolean CheckDeviceHandles(EGLDeviceEXT *devices, EGLint count)
+{
+    EGLint i, j;
+
+    for (i=0; i<count; i++) {
+        for (j=0; j<i; j++) {
+            if (devices[i] == EGL_NO_DEVICE_EXT) {
+                printf("Got EGL_NO_DEVICE_EXT at index %d\n", i);
+                return EGL_FALSE;
+            }
+            if (devices[i] == devices[j]) {
+                printf("Got duplicate device handles at index %d, %d\n", i, j);
+                return EGL_FALSE;
+            }
+        }
+    }
+
+    return EGL_TRUE;
+}
+
+/**
+ * Common function to get a list of devices. This will check to make sure that
+ * we get the number of devices that we expect, that none of them are
+ * EGL_NO_DEVICE_EXT, and that there are no duplicates.
+ */
+EGLBoolean CommonGetDevices(EGLDeviceEXT *devices, EGLint expectedCount)
+{
+    EGLint count = -1;
+
+    if (!ptr_eglQueryDevicesEXT(0, NULL, &count)) {
+        printf("eglQueryDevicesEXT(count) failed\n");
+        return EGL_FALSE;
+    }
+
+    if (count != expectedCount) {
+        printf("eglQueryDevicesEXT(count) returned the wrong count\n");
+        printf("Expected %d, but got %d\n", expectedCount, count);
+        return EGL_FALSE;
+    }
+
+    if (!ptr_eglQueryDevicesEXT(expectedCount, devices, &count)) {
+        printf("eglQueryDevicesEXT(get) failed\n");
+        return EGL_FALSE;
+    }
+
+    if (count != expectedCount) {
+        printf("eglQueryDevicesEXT(ge) returned the wrong count\n");
+        printf("Expected %d, but got %d\n", expectedCount, count);
+        return EGL_FALSE;
+    }
+
+    if (!CheckDeviceHandles(devices, count)) {
+        return EGL_FALSE;
+    }
+
+    return EGL_TRUE;
+}
+
+EGLBoolean CheckDeviceVendors(EGLDeviceEXT *devices, EGLint count, const char *name)
+{
+    EGLint i;
+    for (i=0; i<count; i++)
+    {
+        const char *str = ptr_eglTestDispatchDevice(devices[i], DUMMY_COMMAND_GET_VENDOR_NAME, 0);
+        if (str == NULL) {
+            printf("eglTestDispatchDevice failed at index %s/%d, error 0x%04x\n", name, i, eglGetError());
+            return EGL_FALSE;
+        }
+        if (strcmp(str, name) != 0) {
+            printf("Got the wrong vendor string from device at index %d\n", i);
+            printf("Expected \"%s\", but got \"%s\"\n", name, str);
+            return EGL_FALSE;
+        }
+    }
+
+    return EGL_TRUE;
+}
+
+EGLBoolean TestNewDevice(EGLDeviceEXT newDevice, EGLDeviceEXT *oldDevices, EGLint oldDeviceCount)
+{
+    EGLint i;
+    const char *str;
+
+    if (newDevice == EGL_NO_DEVICE_EXT) {
+        printf("New device is EGL_NO_DEVICE_EXT\n");
+        return EGL_FALSE;
+    }
+
+    // Make sure that the newly added device doesn't show up in the old list
+    for (i=0; i<oldDeviceCount; i++) {
+        if (oldDevices[i] == newDevice) {
+            printf("New device was at index %d\n", i);
+            return EGL_FALSE;
+        }
+    }
+
+    // Make sure we can dispatch using the new device
+    str = ptr_eglTestDispatchDevice(newDevice, DUMMY_COMMAND_GET_VENDOR_NAME, 0);
+    if (str == NULL) {
+        printf("eglTestDispatchDevice failed with new device, error 0x%04x\n", eglGetError());
+        return EGL_FALSE;
+    }
+    if (strcmp(str, DUMMY_VENDOR_NAMES[0]) != 0) {
+        printf("Got the wrong vendor string from device at index %d\n", i);
+        printf("Expected \"%s\", but got \"%s\"\n", DUMMY_VENDOR_NAMES[0], str);
+        return EGL_FALSE;
+    }
+
+    return EGL_TRUE;
+}
+
+EGLBoolean TestAddQueryDevices(EGLDeviceEXT *oldDevices, EGLint oldDeviceCount)
+{
+    EGLDeviceEXT devices[DEVICE_ARRAY_SIZE] = {};
+    EGLint deviceCount = -1;
+    const EGLint expectedDeviceCount = DUMMY_EGL_DEVICE_COUNT * DUMMY_VENDOR_COUNT + 1;
+    EGLDeviceEXT newDevice;
+
+    printf("Testing second eglQueryDevicesEXT call.\n");
+
+    if (!ptr_eglQueryDevicesEXT(DEVICE_ARRAY_SIZE, devices, &deviceCount)) {
+        printf("eglQueryDevicesEXT (2) failed\n");
+        return EGL_FALSE;
+    }
+    if (deviceCount != expectedDeviceCount) {
+        printf("eglQueryDevicesEXT returned the wrong count\n");
+        printf("Expected %d, but got %d\n", expectedDeviceCount, deviceCount);
+        return EGL_FALSE;
+    }
+
+    if (!CheckDeviceHandles(devices, deviceCount)) {
+        return EGL_FALSE;
+    }
+
+    newDevice = devices[DUMMY_EGL_DEVICE_COUNT];
+    return TestNewDevice(newDevice, oldDevices, oldDeviceCount);
+}
+
+EGLBoolean TestReturnDevice(EGLDeviceEXT *oldDevices, EGLint oldDeviceCount)
+{
+    EGLDisplay dpy;
+    EGLint major, minor;
+    EGLDeviceEXT newDevice;
+
+    printf("Testing vendor-provided dispatch function.\n");
+
+    dpy = eglGetPlatformDisplay(EGL_DUMMY_PLATFORM, (EGLNativeDisplayType) DUMMY_VENDOR_NAMES[0], NULL);
+    if (dpy == EGL_NO_DISPLAY) {
+        printf("eglGetPlatformDisplay failed with 0x%04x\n", eglGetError());
+        return EGL_FALSE;
+    }
+    if (!eglInitialize(dpy, &major, &minor)) {
+        printf("eglInitialize failed with 0x%04x\n", eglGetError());
+        return EGL_FALSE;
+    }
+
+    newDevice = ptr_eglTestReturnDevice(dpy, DUMMY_EGL_DEVICE_COUNT);
+    eglTerminate(dpy);
+
+    return TestNewDevice(newDevice, oldDevices, oldDeviceCount);
+}
+
+int main(int argc, char **argv)
+{
+    EGLDeviceEXT devices[DEVICE_ARRAY_SIZE] = {};
+    const EGLint deviceCount = DUMMY_EGL_DEVICE_COUNT * DUMMY_VENDOR_COUNT;
+    EGLint i;
+
+    loadEGLExtensions();
+    loadDummyVendorExtensions();
+
+    printf("Getting initial device list.\n");
+    if (!CommonGetDevices(devices, deviceCount)) {
+        return 1;
+    }
+    // Make sure that we can dispatch using each device
+    for (i=0; i<DUMMY_VENDOR_COUNT; i++) {
+        if (!CheckDeviceVendors(devices + (i * DUMMY_EGL_DEVICE_COUNT),
+                    DUMMY_EGL_DEVICE_COUNT, DUMMY_VENDOR_NAMES[i])) {
+            return 1;
+        }
+    }
+
+    // Add a device to the first vendor.
+    dummyFuncs[0].SetDeviceCount(DUMMY_EGL_DEVICE_COUNT + 1);
+
+    for (i=1; i<argc; i++) {
+        EGLBoolean success = EGL_FALSE;
+        if (strcmp(argv[i], "querydevices") == 0) {
+            success = TestAddQueryDevices(devices, deviceCount);
+        } else if (strcmp(argv[i], "returndevice") == 0) {
+            success = TestReturnDevice(devices, deviceCount);
+        } else {
+            printf("Invalid test name: %s\n", argv[i]);
+        }
+        if (!success) {
+            return 1;
+        }
+    }
+
+    cleanupDummyVendorExtensions();
+    return 0;
+}
+
diff --git a/tests/testegldeviceadd_querydevices.sh b/tests/testegldeviceadd_querydevices.sh
new file mode 100755
index 0000000..e73d2c8
--- /dev/null
+++ b/tests/testegldeviceadd_querydevices.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+
+. $TOP_SRCDIR/tests/eglenv.sh
+
+./testegldeviceadd querydevices
diff --git a/tests/testegldeviceadd_returndevice.sh b/tests/testegldeviceadd_returndevice.sh
new file mode 100755
index 0000000..cf429a9
--- /dev/null
+++ b/tests/testegldeviceadd_returndevice.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+
+. $TOP_SRCDIR/tests/eglenv.sh
+
+./testegldeviceadd returndevice