diff --git a/src/Magnum/DebugTools/CMakeLists.txt b/src/Magnum/DebugTools/CMakeLists.txt
index 2618fbab7..e369aa67a 100644
--- a/src/Magnum/DebugTools/CMakeLists.txt
+++ b/src/Magnum/DebugTools/CMakeLists.txt
@@ -181,6 +181,32 @@ if(BUILD_TESTS)
         endif()
     endif()
 
+    # A subset of DebugTools used by GL's own tests that link to
+    # MagnumGLTestLib (or MagnumOpenGLTesterTestLib), linking also to
+    # MagnumGLTestLibMagnumGL. We can't link those to MagnumDebugToolsTestLib
+    # because it depends on MagnumGL instead, which would lead to the
+    # GL::Context global to be duplicated, causing the dreaded
+    #
+    #   GL::Context::current(): no current context
+    #
+    # assertion. We however also can't link MagnumDebugToolsTestLib to
+    # MagnumGLTestLib, because the other libraries it depends on (MeshTools,
+    # Shaders...) link to MagnumGL and so the same problem would just reappear
+    # elsewhere.
+    if(TARGET_GL AND BUILD_GL_TESTS AND NOT (MAGNUM_TARGET_WEBGL AND MAGNUM_TARGET_GLES2))
+        add_library(MagnumDebugToolsGLTestLibSubset ${SHARED_OR_STATIC}
+            # Add more files if needed
+            BufferData.cpp
+            BufferData.h)
+        set_target_properties(MagnumDebugToolsGLTestLibSubset PROPERTIES DEBUG_POSTFIX "-d")
+        target_compile_definitions(MagnumDebugToolsGLTestLibSubset PRIVATE
+            "CORRADE_GRACEFUL_ASSERT" "MagnumDebugTools_EXPORTS")
+        if(BUILD_STATIC_PIC)
+            set_target_properties(MagnumDebugToolsGLTestLibSubset PROPERTIES POSITION_INDEPENDENT_CODE ON)
+        endif()
+        target_link_libraries(MagnumDebugToolsGLTestLibSubset PUBLIC Magnum MagnumGLTestLib)
+    endif()
+
     add_subdirectory(Test)
 endif()
 
diff --git a/src/Magnum/GL/Test/CMakeLists.txt b/src/Magnum/GL/Test/CMakeLists.txt
index 651848fb5..a51ee2fda 100644
--- a/src/Magnum/GL/Test/CMakeLists.txt
+++ b/src/Magnum/GL/Test/CMakeLists.txt
@@ -92,9 +92,17 @@ if(BUILD_GL_TESTS)
         target_link_libraries(GLBufferGLTest PRIVATE MagnumDebugTools)
     endif()
 
-    corrade_add_test(GLFramebufferGLTest FramebufferGLTest.cpp LIBRARIES MagnumOpenGLTesterTestLib)
+    corrade_add_test(GLFramebufferGLTest FramebufferGLTest.cpp)
+    # See DebugTools/CMakeLists.txt for details about
+    # MagnumDebugToolsGLTestLibSubset. It also has to be before
+    # MagnumOpenGLTesterTestLib to pick GL symbols with CORRADE_GRACEFUL_ASSERT
+    # over ones without... because MagnumOpenGLTesterTestLib is actually
+    # linking to MagnumGL on Linux and macOS.
+    # TODO fix MagnumOpenGLTesterTestLib to link to MagnumGLTestLib always
     if(NOT MAGNUM_TARGET_GLES2)
-        target_link_libraries(GLFramebufferGLTest PRIVATE MagnumDebugTools)
+        target_link_libraries(GLFramebufferGLTest PRIVATE MagnumDebugToolsGLTestLibSubset MagnumOpenGLTesterTestLib)
+    else()
+        target_link_libraries(GLFramebufferGLTest PRIVATE MagnumOpenGLTesterTestLib)
     endif()
 
     corrade_add_test(GLContextGLTest ContextGLTest.cpp LIBRARIES MagnumOpenGLTester)
@@ -170,7 +178,14 @@ if(BUILD_GL_TESTS)
     endif()
 
     if(NOT MAGNUM_TARGET_GLES2)
-        corrade_add_test(GLBufferImageGLTest BufferImageGLTest.cpp LIBRARIES MagnumOpenGLTesterTestLib MagnumDebugTools)
+        # See DebugTools/CMakeLists.txt for details about
+        # MagnumDebugToolsGLTestLibSubset. It also has to be before
+        # MagnumOpenGLTesterTestLib to pick GL symbols with
+        # CORRADE_GRACEFUL_ASSERT over ones without... because
+        # MagnumOpenGLTesterTestLib is actually linking to MagnumGL on Linux
+        # and macOS.
+        # TODO fix MagnumOpenGLTesterTestLib to link to MagnumGLTestLib always
+        corrade_add_test(GLBufferImageGLTest BufferImageGLTest.cpp LIBRARIES MagnumDebugToolsGLTestLibSubset MagnumOpenGLTesterTestLib)
         corrade_add_test(GLPrimitiveQueryGLTest PrimitiveQueryGLTest.cpp LIBRARIES MagnumOpenGLTester)
         corrade_add_test(GLTextureArrayGLTest TextureArrayGLTest.cpp LIBRARIES MagnumOpenGLTester)
         corrade_add_test(GLTransformFeedbackGLTest TransformFeedbackGLTest.cpp LIBRARIES MagnumOpenGLTester MagnumDebugTools)