diff --git a/krita/ui/canvas/kis_mirror_axis.cpp b/krita/ui/canvas/kis_mirror_axis.cpp
--- a/krita/ui/canvas/kis_mirror_axis.cpp
+++ b/krita/ui/canvas/kis_mirror_axis.cpp
@@ -25,6 +25,8 @@
 #include <QToolButton>
 #include <QApplication>
 #include <QPaintEngine>
+#include <QOpenGLContext>
+#include <QOpenGLFunctions>
 
 #include <KoIcon.h>
 
@@ -147,13 +149,16 @@
     gc.setBrush(Qt::white);
     gc.setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
 
-//QT5TODO: T360
-#if defined(HAVE_OPENGL) && defined(HAVE_GLEW)
+#if defined(HAVE_OPENGL)
+    QOpenGLContext *ctx = QOpenGLContext::currentContext();
+    bool hasMultisample = ((gc.paintEngine()->type() == QPaintEngine::OpenGL2) &&
+                           (ctx->hasExtension("GL_ARB_multisample")));
+
     // QPainter cannot anti-alias the edges of circles etc. when using OpenGL
     // So instead, use native OpenGL anti-aliasing when available.
-    if(gc.paintEngine()->type() == QPaintEngine::OpenGL2 && GLEW_ARB_multisample) {
+    if (hasMultisample) {
         gc.beginNativePainting();
-        glEnable(GL_MULTISAMPLE);
+        ctx->functions()->glEnable(GL_MULTISAMPLE);
         gc.endNativePainting();
     }
 #endif
@@ -210,11 +215,10 @@
         }
     }
 
-//QT5TODO: T360
-#if defined(HAVE_OPENGL) && defined(HAVE_GLEW)
-    if(gc.paintEngine()->type() == QPaintEngine::OpenGL2 && GLEW_ARB_multisample) {
+#if defined(HAVE_OPENGL)
+    if (hasMultisample) {
         gc.beginNativePainting();
-        glDisable(GL_MULTISAMPLE);
+        ctx->functions()->glDisable(GL_MULTISAMPLE);
         gc.endNativePainting();
     }
 #endif
diff --git a/krita/ui/opengl/kis_opengl_canvas2_p.h b/krita/ui/opengl/kis_opengl_canvas2_p.h
--- a/krita/ui/opengl/kis_opengl_canvas2_p.h
+++ b/krita/ui/opengl/kis_opengl_canvas2_p.h
@@ -139,7 +139,7 @@
             int interval = ((wglGetSwapIntervalEXT)ctx->getProcAddress("wglGetSwapIntervalEXT"))();
 
             if (interval) {
-                qWarning() << "Failed to disable VSync with WGLEW_EXT_swap_control";
+                qWarning() << "Failed to disable VSync with WGL_EXT_swap_control";
             }
 
             retval = !interval;
diff --git a/krita/ui/opengl/kis_opengl_image_textures.cpp b/krita/ui/opengl/kis_opengl_image_textures.cpp
--- a/krita/ui/opengl/kis_opengl_image_textures.cpp
+++ b/krita/ui/opengl/kis_opengl_image_textures.cpp
@@ -453,7 +453,6 @@
 
     dbgUI << "Choosing texture format:";
 
-// QT5TODO: T360
     if (colorModelId == RGBAColorModelID) {
         if (colorDepthId == Float16BitsColorDepthID) {
 
@@ -471,7 +470,7 @@
             haveBuiltInOpenExr = true;
 #endif
 
-            if (haveBuiltInOpenExr && ctx->hasExtension("GLEW_ARB_half_float_pixel")) {
+            if (haveBuiltInOpenExr && ctx->hasExtension("GL_ARB_half_float_pixel")) {
                 m_texturesInfo.type = GL_HALF_FLOAT_ARB;
                 destinationColorDepthId = Float16BitsColorDepthID;
                 dbgUI << "Pixel type half";
@@ -483,10 +482,10 @@
             m_texturesInfo.format = GL_RGBA;
         }
         else if (colorDepthId == Float32BitsColorDepthID) {
-            if (ctx->hasExtension("GLEW_ARB_texture_float")) {
+            if (ctx->hasExtension("GL_ARB_texture_float")) {
                 m_texturesInfo.internalFormat = GL_RGBA32F_ARB;
                 dbgUI << "Using ARB float";
-            } else if (ctx->hasExtension("GLEW_ATI_texture_float")) {
+            } else if (ctx->hasExtension("GL_ATI_texture_float")) {
                 m_texturesInfo.internalFormat = GL_RGBA_FLOAT32_ATI;
                 dbgUI << "Using ATI float";
             }