diff --git a/doc/changelog.dox b/doc/changelog.dox
index a8b99d2ac..a38236784 100644
--- a/doc/changelog.dox
+++ b/doc/changelog.dox
@@ -441,6 +441,9 @@ namespace Magnum {
     @extension{ARB,direct_state_access} code path, causing crashes on Mesa
 -   Properly export @ref Framebuffer::DrawAttachment to avoid linker failures
     on Windows
+-   On Emscripten, @ref Platform::Sdl2Application was by default rendering a
+    800x600 canvas to an area of 640x480 pixels, causing severe aliasing.
+    Canvas is now by default sized to 640x480 to match the default CSS style.
 -   @ref Platform::WindowlessWglApplication is fixed to allow the GL context to
     be created and destroyed multiple times during application run
 -   @ref SceneGraph::Camera now works properly with @ref Double underlying type
diff --git a/src/Magnum/Platform/Sdl2Application.cpp b/src/Magnum/Platform/Sdl2Application.cpp
index b0b8cd20b..f626117f1 100644
--- a/src/Magnum/Platform/Sdl2Application.cpp
+++ b/src/Magnum/Platform/Sdl2Application.cpp
@@ -529,7 +529,9 @@ Sdl2Application::Configuration::Configuration():
     #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_IOS)
     _title("Magnum SDL2 Application"),
     #endif
-    #ifndef CORRADE_TARGET_IOS
+    #ifdef CORRADE_TARGET_EMSCRIPTEN
+    _size{640, 480},
+    #elif !defined(CORRADE_TARGET_IOS)
     _size{800, 600},
     #else
     _size{}, /* SDL2 detects someting for us */