diff --git a/.github/workflows/ci-pr.yml b/.github/workflows/ci-pr.yml
index 83b9b1996706..819a1bf2e4c0 100644
--- a/.github/workflows/ci-pr.yml
+++ b/.github/workflows/ci-pr.yml
@@ -41,7 +41,7 @@ jobs:
   test-full:
     name: Tests (Full)
     env:
-      FLAGS: --features 'wrap_help yaml regex unstable-replace unstable-multicall'
+      FLAGS: --features 'wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped'
     strategy:
       fail-fast: false
       matrix:
@@ -80,7 +80,7 @@ jobs:
       - name: Default features
         run: cargo check --all-targets
       - name: All features + Debug
-        run: cargo check --all-targets --features "wrap_help yaml regex unstable-replace unstable-multicall debug"
+        run: cargo check --all-targets --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped debug"
       - name: No features
         run: cargo check --all-targets --no-default-features --features "std cargo"
       - name: UI Tests
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2b0f5e3c9413..1c0e86ae9875 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -97,19 +97,19 @@ jobs:
         if: matrix.features == 'all'
         with:
           command: test
-          args: --target ${{ matrix.target }} --features "wrap_help yaml regex unstable-replace unstable-multicall"
+          args: --target ${{ matrix.target }} --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped"
       - name: Check debug
         uses: actions-rs/cargo@v1
         if: matrix.features == 'all'
         with:
           command: check
-          args: --target ${{ matrix.target }} --features "wrap_help yaml regex unstable-replace unstable-multicall debug"
+          args: --target ${{ matrix.target }} --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped debug"
       - name: Test release
         uses: actions-rs/cargo@v1
         if: matrix.features == 'release'
         with:
           command: test
-          args: --target ${{ matrix.target }} --features "wrap_help yaml regex unstable-replace unstable-multicall" --release
+          args: --target ${{ matrix.target }} --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped" --release
   nightly:
     name: Nightly Tests
     strategy:
@@ -139,19 +139,19 @@ jobs:
         if: matrix.features == 'all'
         with:
           command: test
-          args: --features "wrap_help yaml regex unstable-replace unstable-multicall"
+          args: --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped"
       - name: Check debug
         uses: actions-rs/cargo@v1
         if: matrix.features == 'all'
         with:
           command: check
-          args: --features "wrap_help yaml regex unstable-replace unstable-multicall debug"
+          args: --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped debug"
       - name: Test release
         uses: actions-rs/cargo@v1
         if: matrix.features == 'release'
         with:
           command: test
-          args: --features "wrap_help yaml regex unstable-replace unstable-multicall" --release
+          args: --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped" --release
   wasm:
     name: Wasm Check
     runs-on: ubuntu-latest
@@ -172,4 +172,4 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: check
-          args: --target ${{ matrix.target }} --features "yaml regex unstable-replace unstable-multicall"
+          args: --target ${{ matrix.target }} --features "yaml regex unstable-replace unstable-multicall unstable-grouped"
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index eabb04ba1da0..413e5fe5ac30 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -31,7 +31,7 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: llvm-cov
-          args: --features "wrap_help yaml regex unstable-replace unstable-multicall" --lcov --output-path lcov.info
+          args: --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped" --lcov --output-path lcov.info
       - name: Coveralls
         uses: coverallsapp/github-action@master
         with:
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index c0df22a6bd09..d76e8539579f 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -32,7 +32,7 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: clippy
-          args: --features "wrap_help yaml regex unstable-replace unstable-multicall" -- -D warnings
+          args: --features "wrap_help yaml regex unstable-replace unstable-multicall unstable-grouped" -- -D warnings
       - name: Format check
         uses: actions-rs/cargo@v1
         with:
diff --git a/Cargo.toml b/Cargo.toml
index a13e7260a82a..78685a5d9c3d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -118,6 +118,7 @@ yaml = ["yaml-rust"]
 # In-work features
 unstable-replace = []
 unstable-multicall = []
+unstable-grouped = []
 
 [profile.test]
 opt-level = 1
@@ -127,7 +128,7 @@ lto = true
 codegen-units = 1
 
 [package.metadata.docs.rs]
-features = ["yaml", "regex", "unstable-replace", "unstable-multicall"]
+features = ["yaml", "regex", "unstable-replace", "unstable-multicall", "unstable-grouped"]
 targets = ["x86_64-unknown-linux-gnu"]
 
 [workspace]
diff --git a/README.md b/README.md
index 310dfdd85130..b244167bc1c9 100644
--- a/README.md
+++ b/README.md
@@ -478,6 +478,7 @@ These features are opt-in. But be wary that they can contain breaking changes be
 
 * **unstable-replace**: Enable [`App::replace`](https://github.com/clap-rs/clap/issues/2836)
 * **unstable-multicall**: Enable [`AppSettings::Multicall`](https://github.com/clap-rs/clap/issues/2861)
+* **unstable-grouped**: Enable [`ArgMatches::grouped_values_of`](https://github.com/clap-rs/clap/issues/2924)
 
 ### More Information
 
diff --git a/src/parse/matches/arg_matches.rs b/src/parse/matches/arg_matches.rs
index 494f8005f912..eb694bad8c58 100644
--- a/src/parse/matches/arg_matches.rs
+++ b/src/parse/matches/arg_matches.rs
@@ -247,6 +247,7 @@ impl ArgMatches {
     }
 
     /// Placeholder documentation.
+    #[cfg(feature = "unstable-grouped")]
     pub fn grouped_values_of<T: Key>(&self, id: T) -> Option<GroupedValues> {
         #[allow(clippy::type_complexity)]
         let arg_values: for<'a> fn(
diff --git a/tests/grouped_values.rs b/tests/grouped_values.rs
index dd35ac014582..9a295d657134 100644
--- a/tests/grouped_values.rs
+++ b/tests/grouped_values.rs
@@ -1,3 +1,5 @@
+#![cfg(feature = "unstable-grouped")]
+
 mod utils;
 
 use clap::{App, AppSettings, Arg};