diff --git a/collector/benchmarks/README.md b/collector/benchmarks/README.md
index 3747dc0b3..97a7f8bba 100644
--- a/collector/benchmarks/README.md
+++ b/collector/benchmarks/README.md
@@ -100,6 +100,10 @@ programs.
 - **match-stress-exhaustive_patterns**: Contains code extracted from the `syn`
   crate to amplify the perf degradation caused by the `exhaustive_patterns`, as
   measured [here](https://github.com/rust-lang/rust/pull/79394).
+- **projection-caching**: A small program that causes extremely, deeply nested
+  types which stress the trait system's projection cache. Removing that cache
+  resulted in hours long compilations for some programs using futures,
+  actix-web and other libraries with similiarly nested type combinators.
 - **regression-31157**: A small program that caused a [large performance
   regression](https://github.com/rust-lang/rust/issues/31157) from the past.
 - **token-stream-stress**: Constructs a long token stream much like the `quote`
diff --git a/collector/benchmarks/projection-caching/Cargo.lock b/collector/benchmarks/projection-caching/Cargo.lock
new file mode 100644
index 000000000..adaf5378a
--- /dev/null
+++ b/collector/benchmarks/projection-caching/Cargo.lock
@@ -0,0 +1,158 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "futures"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28560757fe2bb34e79f907794bb6b22ae8b0e5c669b638a1132f2592b19035b4"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-executor",
+ "futures-io",
+ "futures-sink",
+ "futures-task",
+ "futures-util",
+]
+
+[[package]]
+name = "futures-channel"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba3dda0b6588335f360afc675d0564c17a77a2bda81ca178a4b6081bd86c7f0b"
+dependencies = [
+ "futures-core",
+ "futures-sink",
+]
+
+[[package]]
+name = "futures-core"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0c8ff0461b82559810cdccfde3215c3f373807f5e5232b71479bff7bb2583d7"
+
+[[package]]
+name = "futures-executor"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29d6d2ff5bb10fb95c85b8ce46538a2e5f5e7fdc755623a7d4529ab8a4ed9d2a"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "futures-util",
+]
+
+[[package]]
+name = "futures-io"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1f9d34af5a1aac6fb380f735fe510746c38067c5bf16c7fd250280503c971b2"
+
+[[package]]
+name = "futures-macro"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6dbd947adfffb0efc70599b3ddcf7b5597bb5fa9e245eb99f62b3a5f7bb8bd3c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "futures-sink"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3055baccb68d74ff6480350f8d6eb8fcfa3aa11bdc1a1ae3afdd0514617d508"
+
+[[package]]
+name = "futures-task"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ee7c6485c30167ce4dfb83ac568a849fe53274c831081476ee13e0dce1aad72"
+
+[[package]]
+name = "futures-util"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b5cf40b47a271f77a8b1bec03ca09044d99d2372c0de244e66430761127164"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-io",
+ "futures-macro",
+ "futures-sink",
+ "futures-task",
+ "memchr",
+ "pin-project-lite",
+ "pin-utils",
+ "slab",
+]
+
+[[package]]
+name = "memchr"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
+
+[[package]]
+name = "pin-project-lite"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e280fbe77cc62c91527259e9442153f4688736748d24660126286329742b4c6c"
+
+[[package]]
+name = "pin-utils"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
+dependencies = [
+ "unicode-xid",
+]
+
+[[package]]
+name = "projection-caching"
+version = "0.1.0"
+dependencies = [
+ "futures",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47aa80447ce4daf1717500037052af176af5d38cc3e571d9ec1c7353fc10c87d"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "slab"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9def91fd1e018fe007022791f865d0ccc9b3a0d5001e01aabb8b40e46000afb5"
+
+[[package]]
+name = "syn"
+version = "1.0.85"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a684ac3dcd8913827e18cd09a68384ee66c1de24157e3c556c9ab16d85695fb7"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
diff --git a/collector/benchmarks/projection-caching/Cargo.toml b/collector/benchmarks/projection-caching/Cargo.toml
new file mode 100644
index 000000000..9347d4ecd
--- /dev/null
+++ b/collector/benchmarks/projection-caching/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "projection-caching"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+futures = "0.3"
+
+[workspace]
diff --git a/collector/benchmarks/projection-caching/src/main.rs b/collector/benchmarks/projection-caching/src/main.rs
new file mode 100644
index 000000000..303b63baa
--- /dev/null
+++ b/collector/benchmarks/projection-caching/src/main.rs
@@ -0,0 +1,23 @@
+use futures::{stream, TryStreamExt};
+
+fn main() {
+    stream::empty::<Result<(), ()>>()
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ())
+        .inspect_ok(|_| ());
+}