diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 01dc83ba..251a3a9b 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -120,3 +120,30 @@ jobs:
         with:
           command: clippy
           args: -- -D warnings
+
+  doc:
+    name: cargo doc
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - run: sudo apt-get install libspeechd-dev
+      - run: cargo doc -p emath -p epaint -p egui -p eframe -p epi -p egui_web -p egui_glium --lib --no-deps --all-features
+
+  doc_web:
+    name: cargo doc web
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - run: sudo apt-get install libspeechd-dev
+      - run: rustup target add wasm32-unknown-unknown
+      - run: cargo doc -p egui_web --target wasm32-unknown-unknown --lib --no-deps --all-features
diff --git a/check.sh b/check.sh
index 82f42f6a..6e8dc0f0 100755
--- a/check.sh
+++ b/check.sh
@@ -13,7 +13,6 @@ CARGO_INCREMENTAL=0 cargo clippy --workspace --all-targets --all-features --  -D
 cargo test --workspace --all-targets --all-features
 cargo fmt --all -- --check
 
-# TODO: make cargo doc produce a proper error (it only prints a warning at the moment).
 cargo doc -p emath -p epaint -p egui -p eframe -p epi -p egui_web -p egui_glium --lib --no-deps --all-features
 cargo doc -p egui_web --target wasm32-unknown-unknown --lib --no-deps --all-features
 
diff --git a/eframe/src/lib.rs b/eframe/src/lib.rs
index 1472a3fc..44e72239 100644
--- a/eframe/src/lib.rs
+++ b/eframe/src/lib.rs
@@ -11,8 +11,11 @@
 //!
 //! `eframe` is implemented using [`egui_web`](https://docs.rs/egui_web) and [`egui_glium`](https://docs.rs/egui_glium).
 
-#![forbid(unsafe_code)]
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
+#![forbid(unsafe_code)]
 #![warn(clippy::all, missing_docs, rust_2018_idioms)]
 
 pub use {egui, epi};
diff --git a/egui/src/context.rs b/egui/src/context.rs
index bca7891e..38186efd 100644
--- a/egui/src/context.rs
+++ b/egui/src/context.rs
@@ -577,8 +577,8 @@ impl Context {
     }
 
     /// Call at the end of each frame.
-    /// Returns what has happened this frame (`Output`) as well as what you need to paint.
-    /// You can transform the returned shapes into triangles with a call to `Context::tessellate`.
+    /// Returns what has happened this frame [`crate::Output`] as well as what you need to paint.
+    /// You can transform the returned shapes into triangles with a call to [`Context::tessellate`].
     #[must_use]
     pub fn end_frame(&self) -> (Output, Vec<ClippedShape>) {
         if self.input.wants_repaint() {
diff --git a/egui/src/lib.rs b/egui/src/lib.rs
index f1b2bd8a..dd64be66 100644
--- a/egui/src/lib.rs
+++ b/egui/src/lib.rs
@@ -237,6 +237,9 @@
 //! ```
 
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
 #![forbid(unsafe_code)]
 #![warn(
     clippy::all,
diff --git a/egui_demo_app/src/lib.rs b/egui_demo_app/src/lib.rs
index fee3863b..8003e052 100644
--- a/egui_demo_app/src/lib.rs
+++ b/egui_demo_app/src/lib.rs
@@ -1,5 +1,8 @@
-#![forbid(unsafe_code)]
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
+#![forbid(unsafe_code)]
 #![warn(clippy::all, rust_2018_idioms)]
 
 #[cfg(target_arch = "wasm32")]
diff --git a/egui_demo_app/src/main.rs b/egui_demo_app/src/main.rs
index 2f005d38..a8cf0bac 100644
--- a/egui_demo_app/src/main.rs
+++ b/egui_demo_app/src/main.rs
@@ -1,5 +1,8 @@
-#![forbid(unsafe_code)]
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
+#![forbid(unsafe_code)]
 #![warn(clippy::all, rust_2018_idioms)]
 
 // When compiling natively:
diff --git a/egui_demo_lib/src/lib.rs b/egui_demo_lib/src/lib.rs
index a4ef95d5..d0a0c0b4 100644
--- a/egui_demo_lib/src/lib.rs
+++ b/egui_demo_lib/src/lib.rs
@@ -3,6 +3,9 @@
 //! The demo-code is also used in benchmarks and tests.
 
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
 #![forbid(unsafe_code)]
 #![warn(
     clippy::all,
diff --git a/egui_glium/src/lib.rs b/egui_glium/src/lib.rs
index 2608a9bb..72b4aef9 100644
--- a/egui_glium/src/lib.rs
+++ b/egui_glium/src/lib.rs
@@ -4,8 +4,11 @@
 //!
 //! If you are writing an app, you may want to look at [`eframe`](https://docs.rs/eframe) instead.
 
-#![forbid(unsafe_code)]
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
+#![forbid(unsafe_code)]
 #![warn(clippy::all, rust_2018_idioms)]
 #![allow(clippy::manual_range_contains, clippy::single_match)]
 
diff --git a/egui_web/src/lib.rs b/egui_web/src/lib.rs
index 78629c61..4b8e5596 100644
--- a/egui_web/src/lib.rs
+++ b/egui_web/src/lib.rs
@@ -4,8 +4,11 @@
 //!
 //! If you are writing an app, you may want to look at [`eframe`](https://docs.rs/eframe) instead.
 
-#![forbid(unsafe_code)]
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
+#![forbid(unsafe_code)]
 #![warn(clippy::all, rust_2018_idioms)]
 
 pub mod backend;
diff --git a/emath/src/lib.rs b/emath/src/lib.rs
index e7db216a..040d5f92 100644
--- a/emath/src/lib.rs
+++ b/emath/src/lib.rs
@@ -10,6 +10,9 @@
 //! * Dimension order is always `x y`
 
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
 #![forbid(unsafe_code)]
 #![warn(
     clippy::all,
diff --git a/epaint/src/lib.rs b/epaint/src/lib.rs
index b9a08320..36d0ebcb 100644
--- a/epaint/src/lib.rs
+++ b/epaint/src/lib.rs
@@ -1,6 +1,9 @@
 //! 2D graphics/rendering. Fonts, textures, color, geometry, tessellation etc.
 
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
 #![forbid(unsafe_code)]
 #![warn(
     clippy::all,
diff --git a/epi/src/lib.rs b/epi/src/lib.rs
index 047f94de..96f8795e 100644
--- a/epi/src/lib.rs
+++ b/epi/src/lib.rs
@@ -7,6 +7,9 @@
 //! Start by looking at the [`App`] trait, and implement [`App::update`].
 
 #![cfg_attr(not(debug_assertions), deny(warnings))] // Forbid warnings in release builds
+#![deny(broken_intra_doc_links)]
+#![deny(invalid_codeblock_attributes)]
+#![deny(private_intra_doc_links)]
 #![forbid(unsafe_code)]
 #![warn(
     clippy::all,