diff --git a/files/en-us/web/api/webglrenderingcontext/compileshader/index.md b/files/en-us/web/api/webglrenderingcontext/compileshader/index.md
index 9cbc7dfb16fb1c6..663dd8a873cc779 100644
--- a/files/en-us/web/api/webglrenderingcontext/compileshader/index.md
+++ b/files/en-us/web/api/webglrenderingcontext/compileshader/index.md
@@ -26,6 +26,11 @@ compileShader(shader)
 
 None ({{jsxref("undefined")}}).
 
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if the specified `shader` is not of type `WebGLShader`.
+
 ## Examples
 
 ```js
diff --git a/files/en-us/web/api/webglrenderingcontext/createshader/index.md b/files/en-us/web/api/webglrenderingcontext/createshader/index.md
index 70a9fb85dba7f98..701ab9761a861a3 100644
--- a/files/en-us/web/api/webglrenderingcontext/createshader/index.md
+++ b/files/en-us/web/api/webglrenderingcontext/createshader/index.md
@@ -23,11 +23,11 @@ createShader(type)
 ### Parameters
 
 - `type`
-  - : Either `gl.VERTEX_SHADER` or `gl.FRAGMENT_SHADER`
+  - : Either `gl.VERTEX_SHADER` or `gl.FRAGMENT_SHADER`. The {{domxref("WebGLRenderingContext")}} will set the `gl.INVALID_ENUM` error flag if an unacceptable value has been specified.
 
 ### Return value
 
-A new ({{domxref("WebGLShader")}}).
+A new {{domxref("WebGLShader")}} instance, or `null` if an error occurs creating the shader (for example, because `type` was an invalid value).
 
 ## Examples
 
diff --git a/files/en-us/web/api/webglrenderingcontext/shadersource/index.md b/files/en-us/web/api/webglrenderingcontext/shadersource/index.md
index 768803bbf242b1c..67803bfd4626f16 100644
--- a/files/en-us/web/api/webglrenderingcontext/shadersource/index.md
+++ b/files/en-us/web/api/webglrenderingcontext/shadersource/index.md
@@ -28,6 +28,11 @@ shaderSource(shader, source)
 
 None ({{jsxref("undefined")}}).
 
+### Exceptions
+
+- {{jsxref("TypeError")}}
+  - : Thrown if the specified `shader` is not of type `WebGLShader`.
+
 ## Examples
 
 ```js