diff --git a/src/Magnum/TextureTools/Test/CMakeLists.txt b/src/Magnum/TextureTools/Test/CMakeLists.txt
index dffd1b322..3aabdefb3 100644
--- a/src/Magnum/TextureTools/Test/CMakeLists.txt
+++ b/src/Magnum/TextureTools/Test/CMakeLists.txt
@@ -25,3 +25,55 @@
 
 corrade_add_test(TextureToolsAtlasTest AtlasTest.cpp LIBRARIES MagnumTextureTools)
 set_target_properties(TextureToolsAtlasTest PROPERTIES FOLDER "Magnum/TextureTools/Test")
+
+if(CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_ANDROID)
+    set(DISTANCEFIELDGLTEST_FILES_DIR "DistanceFieldGLTestFiles")
+else()
+    set(DISTANCEFIELDGLTEST_FILES_DIR ${CMAKE_CURRENT_SOURCE_DIR}/DistanceFieldGLTestFiles)
+endif()
+
+if(BUILD_GL_TESTS)
+    # Otherwise CMake complains that Corrade::PluginManager is not found, wtf
+    find_package(Corrade REQUIRED PluginManager)
+
+    # CMake before 3.8 has broken $<TARGET_FILE*> expressions for iOS (see
+    # https://gitlab.kitware.com/cmake/cmake/merge_requests/404) and since
+    # Corrade doesn't support dynamic plugins on iOS, this sorta works around
+    # that. Should be revisited when updating Travis to newer Xcode (current
+    # has CMake 3.6).
+    if(NOT BUILD_PLUGINS_STATIC)
+        if(WITH_ANYIMAGEIMPORTER)
+            set(ANYIMAGEIMPORTER_PLUGIN_FILENAME $<TARGET_FILE:AnyImageImporter>)
+        endif()
+        if(WITH_TGAIMPORTER)
+            set(TGAIMPORTER_PLUGIN_FILENAME $<TARGET_FILE:TgaImporter>)
+        endif()
+
+        # First replace ${} variables, then $<> generator expressions
+        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/configure.h.cmake
+                       ${CMAKE_CURRENT_BINARY_DIR}/configure.h.in)
+        file(GENERATE OUTPUT $<TARGET_FILE_DIR:TextureToolsDistanceFieldGLTest>/configure.h
+            INPUT ${CMAKE_CURRENT_BINARY_DIR}/configure.h.in)
+    else()
+        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/configure.h.cmake
+                       ${CMAKE_CURRENT_BINARY_DIR}/configure.h)
+    endif()
+
+    corrade_add_test(TextureToolsDistanceFieldGLTest DistanceFieldGLTest.cpp
+        LIBRARIES MagnumTextureTools MagnumGL MagnumTrade MagnumDebugTools MagnumOpenGLTester
+        FILES
+            DistanceFieldGLTestFiles/input.tga
+            DistanceFieldGLTestFiles/output.tga)
+    set_target_properties(TextureToolsDistanceFieldGLTest PROPERTIES FOLDER "Magnum/TextureTools/Test")
+    if(NOT BUILD_PLUGINS_STATIC)
+        target_include_directories(TextureToolsDistanceFieldGLTest PRIVATE $<TARGET_FILE_DIR:TextureToolsDistanceFieldGLTest>)
+    else()
+        target_include_directories(TextureToolsDistanceFieldGLTest PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
+        if(WITH_ANYIMAGEIMPORTER)
+            target_link_libraries(TextureToolsDistanceFieldGLTest PRIVATE AnyImageImporter)
+        endif()
+        if(WITH_TGAIMPORTER)
+            target_link_libraries(TextureToolsDistanceFieldGLTest PRIVATE TgaImporter)
+        endif()
+    endif()
+endif()
diff --git a/src/Magnum/TextureTools/Test/DistanceFieldGLTest.cpp b/src/Magnum/TextureTools/Test/DistanceFieldGLTest.cpp
new file mode 100644
index 000000000..e1d2439ea
--- /dev/null
+++ b/src/Magnum/TextureTools/Test/DistanceFieldGLTest.cpp
@@ -0,0 +1,159 @@
+/*
+    This file is part of Magnum.
+
+    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018
+              Vladimír Vondruš <mosra@centrum.cz>
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included
+    in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS 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 SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+*/
+
+#include <Corrade/PluginManager/AbstractManager.h>
+#include <Corrade/Utility/Directory.h>
+
+#include "Magnum/Image.h"
+#include "Magnum/PixelFormat.h"
+#include "Magnum/Math/Range.h"
+#include "Magnum/DebugTools/CompareImage.h"
+#include "Magnum/DebugTools/TextureImage.h"
+#include "Magnum/GL/Context.h"
+#include "Magnum/GL/Extensions.h"
+#include "Magnum/GL/OpenGLTester.h"
+#include "Magnum/GL/PixelFormat.h"
+#include "Magnum/GL/Texture.h"
+#include "Magnum/GL/TextureFormat.h"
+#include "Magnum/TextureTools/DistanceField.h"
+#include "Magnum/Trade/AbstractImporter.h"
+#include "Magnum/Trade/ImageData.h"
+
+#include "configure.h"
+
+namespace Magnum { namespace TextureTools { namespace Test {
+
+struct DistanceFieldGLTest: GL::OpenGLTester {
+    explicit DistanceFieldGLTest();
+
+    void test();
+
+    private:
+        PluginManager::Manager<Trade::AbstractImporter> _manager;
+};
+
+DistanceFieldGLTest::DistanceFieldGLTest() {
+    addTests({&DistanceFieldGLTest::test});
+
+    /* Load the plugin directly from the build tree. Otherwise it's either
+       static and already loaded or not present in the build tree */
+    #if defined(ANYIMAGEIMPORTER_PLUGIN_FILENAME) && defined(TGAIMPORTER_PLUGIN_FILENAME)
+    CORRADE_INTERNAL_ASSERT(_manager.load(ANYIMAGEIMPORTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
+    CORRADE_INTERNAL_ASSERT(_manager.load(TGAIMPORTER_PLUGIN_FILENAME) & PluginManager::LoadState::Loaded);
+    #endif
+}
+
+void DistanceFieldGLTest::test() {
+    std::unique_ptr<Trade::AbstractImporter> importer;
+    if(!(importer = _manager.loadAndInstantiate("TgaImporter")))
+        CORRADE_SKIP("TgaImporter plugin not found.");
+
+    CORRADE_VERIFY(importer->openFile(Utility::Directory::join(DISTANCEFIELDGLTEST_FILES_DIR, "input.tga")));
+    CORRADE_COMPARE(importer->image2DCount(), 1);
+    Containers::Optional<Trade::ImageData2D> inputImage = importer->image2D(0);
+    CORRADE_VERIFY(inputImage);
+    CORRADE_COMPARE(inputImage->format(), PixelFormat::R8Unorm);
+
+    #ifndef MAGNUM_TARGET_GLES2
+    const GL::TextureFormat inputFormat = GL::TextureFormat::R8;
+    #elif !defined(MAGNUM_TARGET_WEBGL)
+    GL::TextureFormat inputFormat;
+    if(GL::Context::current().isExtensionSupported<GL::Extensions::EXT::texture_rg>())
+        inputFormat = GL::TextureFormat::R8;
+    else
+        inputFormat = GL::TextureFormat::Luminance; /** @todo Luminance8 */
+    #else
+    const GL::TextureFormat inputFormat = GL::TextureFormat::Luminance;
+    #endif
+
+    GL::Texture2D input;
+    input.setMinificationFilter(GL::SamplerFilter::Nearest, GL::SamplerMipmap::Base)
+        .setMagnificationFilter(GL::SamplerFilter::Nearest)
+        .setStorage(1, inputFormat, inputImage->size());
+
+    #if !defined(MAGNUM_TARGET_GLES2) || defined(MAGNUM_TARGET_WEBGL)
+    input.setSubImage(0, {}, *inputImage);
+    #else
+    if(GL::Context::current().isExtensionSupported<GL::Extensions::EXT::texture_rg>())
+        input.setSubImage(0, {}, ImageView2D{inputImage->storage(), GL::PixelFormat::Red, GL::PixelType::UnsignedByte, inputImage->size(), inputImage->data()});
+    else
+        input.setSubImage(0, {}, *inputImage);
+    #endif
+
+    #ifndef MAGNUM_TARGET_GLES2
+    const GL::TextureFormat outputFormat = GL::TextureFormat::R8;
+    #elif !defined(MAGNUM_TARGET_WEBGL)
+    GL::TextureFormat outputFormat;
+    if(GL::Context::current().isExtensionSupported<GL::Extensions::EXT::texture_rg>())
+        outputFormat = GL::TextureFormat::R8;
+    else
+        outputFormat = GL::TextureFormat::Luminance; /** @todo Luminance8 */
+    #else
+    const GL::TextureFormat outputFormat = GL::TextureFormat::Luminance;
+    #endif
+
+    /** @todo luminance is usually not renderable, but with RGBA i would need
+        some TextureTools::swizzle() to get rid of the extra channels for an
+        image compare ... so at the moment, the test just blows up on WebGL 1 */
+
+    GL::Texture2D output;
+    output.setMinificationFilter(GL::SamplerFilter::Nearest, GL::SamplerMipmap::Base)
+        .setMagnificationFilter(GL::SamplerFilter::Nearest)
+        .setStorage(1, outputFormat, Vector2i{64});
+
+    TextureTools::distanceField(input, output, {{}, Vector2i{64}}, 32
+        #ifdef MAGNUM_TARGET_GLES
+        , inputImage->size()
+        #endif
+        );
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+
+    Containers::Optional<Image2D> actualOutputImage;
+    #if !defined(MAGNUM_TARGET_GLES2) || defined(MAGNUM_TARGET_WEBGL)
+    actualOutputImage = Image2D{PixelFormat::R8Unorm};
+    #else
+    if(GL::Context::current().isExtensionSupported<GL::Extensions::EXT::texture_rg>())
+        actualOutputImage = Image2D{GL::PixelFormat::Red, GL::PixelType::UnsignedByte};
+    else
+        actualOutputImage = Image2D{PixelFormat::R8Unorm};
+    #endif
+
+    DebugTools::textureSubImage(output, 0, {{}, Vector2i{64}}, *actualOutputImage);
+
+    MAGNUM_VERIFY_NO_GL_ERROR();
+
+    if(_manager.loadState("AnyImageImporter") == PluginManager::LoadState::NotFound)
+        CORRADE_SKIP("AnyImageImporter plugin not found.");
+
+    /* In some cases actualOutputImage might have GL-specific format,
+       reinterpret as R8Unorm for the comparison to work */
+    CORRADE_COMPARE_WITH((ImageView2D{actualOutputImage->storage(), PixelFormat::R8Unorm, actualOutputImage->size(), actualOutputImage->data()}), Utility::Directory::join(DISTANCEFIELDGLTEST_FILES_DIR, "output.tga"),
+        DebugTools::CompareImageToFile{_manager});
+}
+
+}}}
+
+CORRADE_TEST_MAIN(Magnum::TextureTools::Test::DistanceFieldGLTest)
diff --git a/src/Magnum/TextureTools/Test/DistanceFieldGLTestFiles/input.tga b/src/Magnum/TextureTools/Test/DistanceFieldGLTestFiles/input.tga
new file mode 100644
index 000000000..5ccb2afc1
Binary files /dev/null and b/src/Magnum/TextureTools/Test/DistanceFieldGLTestFiles/input.tga differ
diff --git a/src/Magnum/TextureTools/Test/DistanceFieldGLTestFiles/output.tga b/src/Magnum/TextureTools/Test/DistanceFieldGLTestFiles/output.tga
new file mode 100644
index 000000000..278ec6a32
Binary files /dev/null and b/src/Magnum/TextureTools/Test/DistanceFieldGLTestFiles/output.tga differ
diff --git a/src/Magnum/TextureTools/Test/configure.h.cmake b/src/Magnum/TextureTools/Test/configure.h.cmake
new file mode 100644
index 000000000..bb4fbf1c2
--- /dev/null
+++ b/src/Magnum/TextureTools/Test/configure.h.cmake
@@ -0,0 +1,28 @@
+/*
+    This file is part of Magnum.
+
+    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018
+              Vladimír Vondruš <mosra@centrum.cz>
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included
+    in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS 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 SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+*/
+
+#cmakedefine ANYIMAGEIMPORTER_PLUGIN_FILENAME "${ANYIMAGEIMPORTER_PLUGIN_FILENAME}"
+#cmakedefine TGAIMPORTER_PLUGIN_FILENAME "${TGAIMPORTER_PLUGIN_FILENAME}"
+#define DISTANCEFIELDGLTEST_FILES_DIR "${DISTANCEFIELDGLTEST_FILES_DIR}"