diff --git a/src/Magnum/GL/Buffer.cpp b/src/Magnum/GL/Buffer.cpp
index b3b544cda..d839f4fd7 100644
--- a/src/Magnum/GL/Buffer.cpp
+++ b/src/Magnum/GL/Buffer.cpp
@@ -329,7 +329,7 @@ Int Buffer::size() {
     return size;
 }
 
-#ifndef MAGNUM_TARGET_GLES
+#if !defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_WEBGL) && !defined(MAGNUM_TARGET_GLES2) && __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 20017)
 Containers::Array<char> Buffer::data() {
     return subData(0, size());
 }
@@ -372,7 +372,7 @@ Buffer& Buffer::flushMappedRange(const GLintptr offset, const GLsizeiptr length)
 bool Buffer::unmap() { return (this->*Context::current().state().buffer.unmapImplementation)(); }
 #endif
 
-#ifndef MAGNUM_TARGET_GLES
+#if !defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_WEBGL) && !defined(MAGNUM_TARGET_GLES2) && __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 20017)
 Containers::Array<char> Buffer::subData(const GLintptr offset, const GLsizeiptr size) {
     Containers::Array<char> data(size);
     if(size) (this->*Context::current().state().buffer.getSubDataImplementation)(offset, size, data);
@@ -468,11 +468,13 @@ void Buffer::getParameterImplementationDSA(const GLenum value, GLint* const data
 }
 #endif
 
-#ifndef MAGNUM_TARGET_GLES
+#if !defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_WEBGL) && !defined(MAGNUM_TARGET_GLES2) && __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 20017)
 void Buffer::getSubDataImplementationDefault(const GLintptr offset, const GLsizeiptr size, GLvoid* const data) {
     glGetBufferSubData(GLenum(bindSomewhereInternal(_targetHint)), offset, size, data);
 }
+#endif
 
+#ifndef MAGNUM_TARGET_GLES
 void Buffer::getSubDataImplementationDSA(const GLintptr offset, const GLsizeiptr size, GLvoid* const data) {
     glGetNamedBufferSubData(_id, offset, size, data);
 }
diff --git a/src/Magnum/GL/Buffer.h b/src/Magnum/GL/Buffer.h
index 076626f50..b88178298 100644
--- a/src/Magnum/GL/Buffer.h
+++ b/src/Magnum/GL/Buffer.h
@@ -1089,7 +1089,7 @@ class MAGNUM_GL_EXPORT Buffer: public AbstractObject {
          */
         Int size();
 
-        #ifndef MAGNUM_TARGET_GLES
+        #if !defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_WEBGL) && !defined(MAGNUM_TARGET_GLES2) && __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 20017)
         /**
          * @brief Buffer data
          *
@@ -1101,9 +1101,11 @@ class MAGNUM_GL_EXPORT Buffer: public AbstractObject {
          *      eventually @fn_gl{BindBuffer} and @fn_gl{GetBufferParameter}
          *      with @def_gl{BUFFER_SIZE}, then @fn_gl2_keyword{GetNamedBufferSubData,GetBufferSubData},
          *      eventually @fn_gl_keyword{GetBufferSubData}
-         * @requires_gl Buffer data queries are not available in OpenGL ES and
-         *      WebGL. Use @ref map(), @ref mapRead() or @ref DebugTools::bufferData()
-         *      in OpenGL ES instead.
+         * @requires_gl Buffer data queries are not available in OpenGL ES. Use
+         *      @ref map(), @ref mapRead() or @ref DebugTools::bufferData()
+         *      instead.
+         * @requires_webgl20 Buffer data queries are not available in
+         *      WebGL 1.0. Emscripten 2.0.17 or higher is required in WebGL2.
          */
         Containers::Array<char> data();
 
@@ -1119,9 +1121,11 @@ class MAGNUM_GL_EXPORT Buffer: public AbstractObject {
          * @see @ref size(), @ref data(), @ref setSubData(), @ref setTargetHint(),
          *      @fn_gl2_keyword{GetNamedBufferSubData,GetBufferSubData},
          *      eventually @fn_gl{BindBuffer} and @fn_gl_keyword{GetBufferSubData}
-         * @requires_gl Buffer data queries are not available in OpenGL ES and
-         *      WebGL. Use @ref map(), @ref mapRead() or @ref DebugTools::bufferData()
-         *      in OpenGL ES instead.
+         * @requires_gl Buffer data queries are not available in OpenGL ES. Use
+         *      @ref map(), @ref mapRead() or @ref DebugTools::bufferData() in
+         *      OpenGL ES instead.
+         * @requires_webgl20 Buffer data queries are not available in
+         *      WebGL 1.0. Emscripten 2.0.17 or higher is required in WebGL2.
          */
         Containers::Array<char> subData(GLintptr offset, GLsizeiptr size);
         #endif
@@ -1357,8 +1361,10 @@ class MAGNUM_GL_EXPORT Buffer: public AbstractObject {
         void MAGNUM_GL_LOCAL getParameterImplementationDSA(GLenum value, GLint* data);
         #endif
 
-        #ifndef MAGNUM_TARGET_GLES
+        #if !defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_WEBGL) && !defined(MAGNUM_TARGET_GLES2) && __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 20017)
         void MAGNUM_GL_LOCAL getSubDataImplementationDefault(GLintptr offset, GLsizeiptr size, GLvoid* data);
+        #endif
+        #ifndef MAGNUM_TARGET_GLES
         void MAGNUM_GL_LOCAL getSubDataImplementationDSA(GLintptr offset, GLsizeiptr size, GLvoid* data);
         #endif
 
diff --git a/src/Magnum/GL/Implementation/BufferState.cpp b/src/Magnum/GL/Implementation/BufferState.cpp
index f71a53769..e1dbb85ad 100644
--- a/src/Magnum/GL/Implementation/BufferState.cpp
+++ b/src/Magnum/GL/Implementation/BufferState.cpp
@@ -126,7 +126,7 @@ BufferState::BufferState(Context& context, Containers::StaticArrayView<Implement
         storageImplementation = &Buffer::storageImplementationDefault;
         #endif
         getParameterImplementation = &Buffer::getParameterImplementationDefault;
-        #ifndef MAGNUM_TARGET_GLES
+        #if !defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_WEBGL) && !defined(MAGNUM_TARGET_GLES2) && __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 20017)
         getSubDataImplementation = &Buffer::getSubDataImplementationDefault;
         #endif
         dataImplementation = &Buffer::dataImplementationDefault;
diff --git a/src/Magnum/GL/Implementation/BufferState.h b/src/Magnum/GL/Implementation/BufferState.h
index 93b74a08a..32760a70c 100644
--- a/src/Magnum/GL/Implementation/BufferState.h
+++ b/src/Magnum/GL/Implementation/BufferState.h
@@ -59,7 +59,7 @@ struct BufferState {
     void(Buffer::*storageImplementation)(Containers::ArrayView<const void>, Buffer::StorageFlags);
     #endif
     void(Buffer::*getParameterImplementation)(GLenum, GLint*);
-    #ifndef MAGNUM_TARGET_GLES2
+    #if !defined(MAGNUM_TARGET_GLES) || (defined(MAGNUM_TARGET_WEBGL) && !defined(MAGNUM_TARGET_GLES2) && __EMSCRIPTEN_major__*10000 + __EMSCRIPTEN_minor__*100 + __EMSCRIPTEN_tiny__ >= 20017)
     void(Buffer::*getSubDataImplementation)(GLintptr, GLsizeiptr, GLvoid*);
     #endif
     void(Buffer::*dataImplementation)(GLsizeiptr, const GLvoid*, BufferUsage);