diff --git a/dom/canvas/WebGL2Context.h b/dom/canvas/WebGL2Context.h
index fe4ddab7cbe3..045cbb11b40a 100644
--- a/dom/canvas/WebGL2Context.h
+++ b/dom/canvas/WebGL2Context.h
@@ -55,13 +55,20 @@ public:
     void BlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
                          GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
                          GLbitfield mask, GLenum filter);
-    void FramebufferTextureLayer(GLenum target, GLenum attachment, GLuint texture, GLint level, GLint layer);
-    void GetInternalformatParameter(JSContext*, GLenum target, GLenum internalformat, GLenum pname, JS::MutableHandleValue retval);
+    void FramebufferTextureLayer(GLenum target, GLenum attachment, WebGLTexture* texture, GLint level, GLint layer);
     void InvalidateFramebuffer(GLenum target, const dom::Sequence<GLenum>& attachments,
                                ErrorResult& rv);
     void InvalidateSubFramebuffer (GLenum target, const dom::Sequence<GLenum>& attachments, GLint x, GLint y,
                                    GLsizei width, GLsizei height, ErrorResult& rv);
     void ReadBuffer(GLenum mode);
+
+
+    // -------------------------------------------------------------------------
+    // Renderbuffer objects - WebGL2ContextRenderbuffers.cpp
+
+    void GetInternalformatParameter(JSContext*, GLenum target, GLenum internalformat,
+                                    GLenum pname, JS::MutableHandleValue retval,
+                                    ErrorResult& rv);
     void RenderbufferStorageMultisample(GLenum target, GLsizei samples, GLenum internalformat,
                                         GLsizei width, GLsizei height);
 
diff --git a/dom/canvas/WebGL2ContextFramebuffers.cpp b/dom/canvas/WebGL2ContextFramebuffers.cpp
index a50071e089bb..ab09fc1eb9a3 100644
--- a/dom/canvas/WebGL2ContextFramebuffers.cpp
+++ b/dom/canvas/WebGL2ContextFramebuffers.cpp
@@ -336,12 +336,6 @@ WebGL2Context::FramebufferTextureLayer(GLenum target, GLenum attachment, GLuint
     GenerateWarning("framebufferTextureLayer: Not Implemented.");
 }
 
-void
-WebGL2Context::GetInternalformatParameter(JSContext*, GLenum target, GLenum internalformat, GLenum pname, JS::MutableHandleValue retval)
-{
-    GenerateWarning("getInternalformatParameter: Not Implemented.");
-}
-
 // Map attachments intended for the default buffer, to attachments for a non-
 // default buffer.
 static bool
@@ -536,13 +530,4 @@ WebGL2Context::ReadBuffer(GLenum mode)
     gl->Screen()->SetReadBuffer(mode);
 }
 
-void
-WebGL2Context::RenderbufferStorageMultisample(GLenum target, GLsizei samples,
-                                              GLenum internalFormat,
-                                              GLsizei width, GLsizei height)
-{
-    RenderbufferStorage_base("renderbufferStorageMultisample", target, samples,
-                              internalFormat, width, height);
-}
-
 } // namespace mozilla
diff --git a/dom/canvas/WebGL2ContextRenderbuffers.cpp b/dom/canvas/WebGL2ContextRenderbuffers.cpp
new file mode 100644
index 000000000000..7ad686414a3a
--- /dev/null
+++ b/dom/canvas/WebGL2ContextRenderbuffers.cpp
@@ -0,0 +1,66 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "WebGL2Context.h"
+
+#include "GLContext.h"
+#include "WebGLContextUtils.h"
+
+namespace mozilla {
+
+void
+WebGL2Context::GetInternalformatParameter(JSContext* cx, GLenum target,
+                                          GLenum internalformat, GLenum pname,
+                                          JS::MutableHandleValue retval,
+                                          ErrorResult& rv)
+{
+  if (IsContextLost())
+    return;
+
+  if (target != LOCAL_GL_RENDERBUFFER) {
+    return ErrorInvalidEnumInfo("getInternalfomratParameter: target must be "
+                                "RENDERBUFFER. Was:", target);
+  }
+
+  // GL_INVALID_ENUM is generated if internalformat is not color-,
+  // depth-, or stencil-renderable.
+  // TODO: When format table queries lands.
+
+  if (pname != LOCAL_GL_SAMPLES) {
+    return ErrorInvalidEnumInfo("getInternalformatParameter: pname must be SAMPLES. "
+                                "Was:", pname);
+  }
+
+  GLint* samples = nullptr;
+  GLint sampleCount = 0;
+  gl->fGetInternalformativ(LOCAL_GL_RENDERBUFFER, internalformat,
+                           LOCAL_GL_NUM_SAMPLE_COUNTS, 1, &sampleCount);
+  if (sampleCount > 0) {
+    samples = new GLint[sampleCount];
+    gl->fGetInternalformativ(LOCAL_GL_RENDERBUFFER, internalformat, LOCAL_GL_SAMPLES,
+                             sampleCount, samples);
+  }
+
+  JSObject* obj = dom::Int32Array::Create(cx, this, sampleCount, samples);
+  if (!obj) {
+    rv = NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  delete[] samples;
+
+  retval.setObjectOrNull(obj);
+}
+
+void
+WebGL2Context::RenderbufferStorageMultisample(GLenum target, GLsizei samples,
+                                              GLenum internalFormat,
+                                              GLsizei width, GLsizei height)
+{
+  RenderbufferStorage_base("renderbufferStorageMultisample", target, samples,
+                           internalFormat, width, height);
+}
+
+} // namespace mozilla
diff --git a/dom/canvas/moz.build b/dom/canvas/moz.build
index 57984a648eb5..c859d726e986 100644
--- a/dom/canvas/moz.build
+++ b/dom/canvas/moz.build
@@ -60,6 +60,7 @@ UNIFIED_SOURCES += [
     'WebGL2ContextMRTs.cpp',
     'WebGL2ContextPrograms.cpp',
     'WebGL2ContextQueries.cpp',
+    'WebGL2ContextRenderbuffers.cpp',
     'WebGL2ContextSamplers.cpp',
     'WebGL2ContextState.cpp',
     'WebGL2ContextSync.cpp',
diff --git a/dom/webidl/WebGL2RenderingContext.webidl b/dom/webidl/WebGL2RenderingContext.webidl
index 30e4c9e16a7f..3be96123809f 100644
--- a/dom/webidl/WebGL2RenderingContext.webidl
+++ b/dom/webidl/WebGL2RenderingContext.webidl
@@ -323,8 +323,7 @@ interface WebGL2RenderingContext : WebGLRenderingContext
     /* Framebuffer objects */
     void blitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0,
                          GLint dstX1, GLint dstY1, GLbitfield mask, GLenum filter);
-    void framebufferTextureLayer(GLenum target, GLenum attachment, GLuint texture, GLint level, GLint layer);
-    any getInternalformatParameter(GLenum target, GLenum internalformat, GLenum pname);
+    void framebufferTextureLayer(GLenum target, GLenum attachment, WebGLTexture? texture, GLint level, GLint layer);
 
     [Throws]
     void invalidateFramebuffer(GLenum target, sequence<GLenum> attachments);
@@ -336,6 +335,8 @@ interface WebGL2RenderingContext : WebGLRenderingContext
     void readBuffer(GLenum src);
 
     /* Renderbuffer objects */
+    [Throws]
+    any getInternalformatParameter(GLenum target, GLenum internalformat, GLenum pname);
     void renderbufferStorageMultisample(GLenum target, GLsizei samples, GLenum internalformat, GLsizei width, GLsizei height);
 
     /* Texture objects */