diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e33e624f6..1af234c7e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -159,3 +159,18 @@ jobs:
     - if: "!startsWith(matrix.os, 'windows')"
       run: cargo test
       name: Run tests (not Windows)
+
+  test-fips:
+    name: Test FIPS integration
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: 'recursive'
+    - name: Install Rust (rustup)
+      run: rustup update stable --no-self-update && rustup default stable
+      shell: bash
+    - name: Install Clang-7
+      run: sudo apt-get install -y clang-7
+    - run: cargo test --features fips
+      name: Run tests
diff --git a/.gitmodules b/.gitmodules
index 53b702f01..93bfb089f 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,4 +1,7 @@
 [submodule "boring-sys/deps/boringssl"]
 	path = boring-sys/deps/boringssl
 	url = https://github.com/google/boringssl.git
-	ignore = dirty
\ No newline at end of file
+	ignore = dirty
+[submodule "boring-sys/deps/boringssl-fips"]
+	path = boring-sys/deps/boringssl-fips
+	url = https://github.com/google/boringssl.git
diff --git a/README.md b/README.md
index 75e9718b2..da8442105 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,18 @@ _Notes_: The crate will look for headers in the `$BORING_BSSL_INCLUDE_PATH/opens
 
 _Warning_: When providing a different version of BoringSSL make sure to use a compatible one, the crate relies on the presence of certain functions.
 
+## Building with a FIPS-validated module
+
+Only BoringCrypto module version ae223d6138807a13006342edfeef32e813246b39, as
+certified with [certificate
+3678](https://csrc.nist.gov/projects/cryptographic-module-validation-program/certificate/3678)
+is supported by this crate. Support is enabled by this crate's `fips` feature.
+
+`boring-sys` comes with a test that FIPS is enabled/disabled depending on the feature flag. You can run it as follows:
+```bash
+$ cargo test --features fips fips::is_enabled
+```
+
 ## Contribution
 
 Unless you explicitly state otherwise, any contribution intentionally
diff --git a/boring-sys/Cargo.toml b/boring-sys/Cargo.toml
index d0da3a187..59bf5cfe9 100644
--- a/boring-sys/Cargo.toml
+++ b/boring-sys/Cargo.toml
@@ -29,3 +29,7 @@ include = [
 [build-dependencies]
 bindgen = { version = "0.59", default-features = false, features = ["runtime"] }
 cmake = "0.1"
+
+[features]
+# Use a FIPS-validated version of boringssl.
+fips = []
diff --git a/boring-sys/build.rs b/boring-sys/build.rs
index 8a848a796..513b8bcf7 100644
--- a/boring-sys/build.rs
+++ b/boring-sys/build.rs
@@ -1,3 +1,6 @@
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
 // NOTE: this build script is adopted from quiche (https://github.com/cloudflare/quiche)
 
 // Additional parameters for Android build of BoringSSL.
@@ -85,6 +88,11 @@ fn get_boringssl_platform_output_path() -> String {
     }
 }
 
+#[cfg(feature = "fips")]
+const BORING_SSL_PATH: &str = "deps/boringssl-fips";
+#[cfg(not(feature = "fips"))]
+const BORING_SSL_PATH: &str = "deps/boringssl";
+
 /// Returns a new cmake::Config for building BoringSSL.
 ///
 /// It will add platform-specific parameters if needed.
@@ -93,7 +101,7 @@ fn get_boringssl_cmake_config() -> cmake::Config {
     let os = std::env::var("CARGO_CFG_TARGET_OS").unwrap();
     let pwd = std::env::current_dir().unwrap();
 
-    let mut boringssl_cmake = cmake::Config::new("deps/boringssl");
+    let mut boringssl_cmake = cmake::Config::new(BORING_SSL_PATH);
 
     // Add platform-specific parameters.
     match os.as_ref() {
@@ -105,6 +113,7 @@ fn get_boringssl_cmake_config() -> cmake::Config {
             };
 
             // We need ANDROID_NDK_HOME to be set properly.
+            println!("cargo:rerun-if-env-changed=ANDROID_NDK_HOME");
             let android_ndk_home = std::env::var("ANDROID_NDK_HOME")
                 .expect("Please set ANDROID_NDK_HOME for Android build");
             let android_ndk_home = std::path::Path::new(&android_ndk_home);
@@ -161,7 +170,8 @@ fn get_boringssl_cmake_config() -> cmake::Config {
             if arch == "x86" && os != "windows" {
                 boringssl_cmake.define(
                     "CMAKE_TOOLCHAIN_FILE",
-                    pwd.join("deps/boringssl/src/util/32-bit-toolchain.cmake")
+                    pwd.join(BORING_SSL_PATH)
+                        .join("src/util/32-bit-toolchain.cmake")
                         .as_os_str(),
                 );
             }
@@ -171,42 +181,107 @@ fn get_boringssl_cmake_config() -> cmake::Config {
     }
 }
 
-fn main() {
-    use std::env;
-    use std::path::{Path, PathBuf};
-    use std::process::Command;
-
-    if !Path::new("deps/boringssl/CMakeLists.txt").exists() {
-        println!("cargo:warning=fetching boringssl git submodule");
-        // fetch the boringssl submodule
-        let status = Command::new("git")
-            .args(&[
-                "submodule",
-                "update",
-                "--init",
-                "--recursive",
-                "deps/boringssl",
-            ])
-            .status();
-        if !status.map_or(false, |status| status.success()) {
-            panic!("failed to fetch submodule - consider running `git submodule update --init --recursive deps/boringssl` yourself");
+/// Verify that the toolchains match https://csrc.nist.gov/CSRC/media/projects/cryptographic-module-validation-program/documents/security-policies/140sp3678.pdf
+/// See "Installation Instructions" under section 12.1.
+// TODO: maybe this should also verify the Go and Ninja versions? But those haven't been an issue in practice ...
+fn verify_fips_clang_version() -> (&'static str, &'static str) {
+    fn version(tool: &str) -> String {
+        let output = match Command::new(tool).arg("--version").output() {
+            Ok(o) => o,
+            Err(e) => {
+                eprintln!("warning: missing {}, trying other compilers: {}", tool, e);
+                // NOTE: hard-codes that the loop below checks the version
+                return String::new();
+            }
+        };
+        assert!(output.status.success());
+        let output = std::str::from_utf8(&output.stdout).expect("invalid utf8 output");
+        output.lines().next().expect("empty output").to_string()
+    }
+
+    const REQUIRED_CLANG_VERSION: &str = "7.0.1";
+    for (cc, cxx) in [
+        ("clang-7", "clang++-7"),
+        ("clang", "clang++"),
+        ("cc", "c++"),
+    ] {
+        let cc_version = version(cc);
+        if cc_version.contains(REQUIRED_CLANG_VERSION) {
+            assert!(
+                version(cxx).contains(REQUIRED_CLANG_VERSION),
+                "mismatched versions of cc and c++"
+            );
+            return (cc, cxx);
+        } else if cc == "cc" {
+            panic!(
+                "unsupported clang version \"{}\": FIPS requires clang {}",
+                cc_version, REQUIRED_CLANG_VERSION
+            );
+        } else if !cc_version.is_empty() {
+            eprintln!(
+                "warning: FIPS requires clang version {}, skipping incompatible version \"{}\"",
+                REQUIRED_CLANG_VERSION, cc_version
+            );
         }
     }
+    unreachable!()
+}
+
+fn main() {
+    use std::env;
 
+    println!("cargo:rerun-if-env-changed=BORING_BSSL_PATH");
     let bssl_dir = std::env::var("BORING_BSSL_PATH").unwrap_or_else(|_| {
+        if !Path::new(BORING_SSL_PATH).join("CMakeLists.txt").exists() {
+            println!("cargo:warning=fetching boringssl git submodule");
+            // fetch the boringssl submodule
+            let status = Command::new("git")
+                .args(&[
+                    "submodule",
+                    "update",
+                    "--init",
+                    "--recursive",
+                    BORING_SSL_PATH,
+                ])
+                .status();
+            if !status.map_or(false, |status| status.success()) {
+                panic!("failed to fetch submodule - consider running `git submodule update --init --recursive deps/boringssl` yourself");
+            }
+        }
+
         let mut cfg = get_boringssl_cmake_config();
 
         if cfg!(feature = "fuzzing") {
             cfg.cxxflag("-DBORINGSSL_UNSAFE_DETERMINISTIC_MODE")
                 .cxxflag("-DBORINGSSL_UNSAFE_FUZZER_MODE");
         }
+        if cfg!(feature = "fips") {
+            let (clang, clangxx) = verify_fips_clang_version();
+            cfg.define("CMAKE_C_COMPILER", clang);
+            cfg.define("CMAKE_CXX_COMPILER", clangxx);
+            cfg.define("CMAKE_ASM_COMPILER", clang);
+            cfg.define("FIPS", "1");
+        }
 
         cfg.build_target("bssl").build().display().to_string()
     });
 
     let build_path = get_boringssl_platform_output_path();
-    let build_dir = format!("{}/build/{}", bssl_dir, build_path);
-    println!("cargo:rustc-link-search=native={}", build_dir);
+    if cfg!(feature = "fips") {
+        println!(
+            "cargo:rustc-link-search=native={}/build/crypto/{}",
+            bssl_dir, build_path
+        );
+        println!(
+            "cargo:rustc-link-search=native={}/build/ssl/{}",
+            bssl_dir, build_path
+        );
+    } else {
+        println!(
+            "cargo:rustc-link-search=native={}/build/{}",
+            bssl_dir, build_path
+        );
+    }
 
     println!("cargo:rustc-link-lib=static=crypto");
     println!("cargo:rustc-link-lib=static=ssl");
@@ -216,10 +291,14 @@ fn main() {
         println!("cargo:rustc-cdylib-link-arg=-Wl,-undefined,dynamic_lookup");
     }
 
-    let include_path = PathBuf::from(
-        std::env::var("BORING_BSSL_INCLUDE_PATH")
-            .unwrap_or_else(|_| String::from("deps/boringssl/src/include")),
-    );
+    println!("cargo:rerun-if-env-changed=BORING_BSSL_INCLUDE_PATH");
+    let include_path = std::env::var("BORING_BSSL_INCLUDE_PATH").unwrap_or_else(|_| {
+        if cfg!(feature = "fips") {
+            format!("{}/include", BORING_SSL_PATH)
+        } else {
+            format!("{}/src/include", BORING_SSL_PATH)
+        }
+    });
 
     let mut builder = bindgen::Builder::default()
         .derive_copy(true)
@@ -234,12 +313,13 @@ fn main() {
         .layout_tests(true)
         .prepend_enum_name(true)
         .rustfmt_bindings(true)
-        .clang_args(&["-I", include_path.to_str().unwrap()]);
+        .clang_args(&["-I", &include_path]);
 
     let headers = [
         "aes.h",
         "asn1_mac.h",
         "asn1t.h",
+        #[cfg(not(feature = "fips"))]
         "blake2.h",
         "blowfish.h",
         "cast.h",
@@ -264,11 +344,18 @@ fn main() {
         "ripemd.h",
         "siphash.h",
         "srtp.h",
+        #[cfg(not(feature = "fips"))]
         "trust_token.h",
         "x509v3.h",
     ];
     for header in &headers {
-        builder = builder.header(include_path.join("openssl").join(header).to_str().unwrap());
+        builder = builder.header(
+            Path::new(&include_path)
+                .join("openssl")
+                .join(header)
+                .to_str()
+                .unwrap(),
+        );
     }
 
     let bindings = builder.generate().expect("Unable to generate bindings");
diff --git a/boring-sys/deps/boringssl-fips b/boring-sys/deps/boringssl-fips
new file mode 160000
index 000000000..ae223d613
--- /dev/null
+++ b/boring-sys/deps/boringssl-fips
@@ -0,0 +1 @@
+Subproject commit ae223d6138807a13006342edfeef32e813246b39
diff --git a/boring/Cargo.toml b/boring/Cargo.toml
index 72d011759..5d58c2756 100644
--- a/boring/Cargo.toml
+++ b/boring/Cargo.toml
@@ -21,3 +21,7 @@ boring-sys = { version = ">=1.1.0,<3.0.0", path = "../boring-sys" }
 [dev-dependencies]
 hex = "0.4"
 rusty-hook = "^0.11"
+
+[features]
+# Use a FIPS-validated version of boringssl.
+fips = ["boring-sys/fips"]
diff --git a/boring/examples/fips_enabled.rs b/boring/examples/fips_enabled.rs
new file mode 100644
index 000000000..7a57aee4f
--- /dev/null
+++ b/boring/examples/fips_enabled.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("boring::fips::enabled(): {}", boring::fips::enabled());
+}
diff --git a/boring/examples/mk_certs.rs b/boring/examples/mk_certs.rs
index 217786e26..b27b3974c 100644
--- a/boring/examples/mk_certs.rs
+++ b/boring/examples/mk_certs.rs
@@ -81,6 +81,7 @@ fn mk_request(privkey: &PKey<Private>) -> Result<X509Req, ErrorStack> {
 }
 
 /// Make a certificate and private key signed by the given CA cert and private key
+#[cfg_attr(feature = "fips", allow(unreachable_code, unused_variables))]
 fn mk_ca_signed_cert(
     ca_cert: &X509Ref,
     ca_privkey: &PKeyRef<Private>,
@@ -98,7 +99,15 @@ fn mk_ca_signed_cert(
         serial.to_asn1_integer()?
     };
     cert_builder.set_serial_number(&serial_number)?;
+
+    #[cfg(not(feature = "fips"))]
     cert_builder.set_subject_name(req.subject_name())?;
+    #[cfg(feature = "fips")]
+    {
+        eprintln!("mk_certs not supported with FIPS module");
+        std::process::exit(1);
+    }
+
     cert_builder.set_issuer_name(ca_cert.subject_name())?;
     cert_builder.set_pubkey(&privkey)?;
     let not_before = Asn1Time::days_from_now(0)?;
diff --git a/boring/src/fips.rs b/boring/src/fips.rs
index 2d68633d7..baf044f74 100644
--- a/boring/src/fips.rs
+++ b/boring/src/fips.rs
@@ -20,3 +20,11 @@ pub fn enable(enabled: bool) -> Result<(), ErrorStack> {
 pub fn enabled() -> bool {
     unsafe { ffi::FIPS_mode() != 0 }
 }
+
+#[test]
+fn is_enabled() {
+    #[cfg(feature = "fips")]
+    assert!(enabled());
+    #[cfg(not(feature = "fips"))]
+    assert!(!enabled());
+}
diff --git a/boring/src/pkey.rs b/boring/src/pkey.rs
index c62ee341d..4054abd12 100644
--- a/boring/src/pkey.rs
+++ b/boring/src/pkey.rs
@@ -76,8 +76,10 @@ impl Id {
     pub const DH: Id = Id(ffi::EVP_PKEY_DH);
     pub const EC: Id = Id(ffi::EVP_PKEY_EC);
     pub const ED25519: Id = Id(ffi::EVP_PKEY_ED25519);
+    #[cfg(not(feature = "fips"))]
     pub const ED448: Id = Id(ffi::EVP_PKEY_ED448);
     pub const X25519: Id = Id(ffi::EVP_PKEY_X25519);
+    #[cfg(not(feature = "fips"))]
     pub const X448: Id = Id(ffi::EVP_PKEY_X448);
 
     /// Creates a `Id` from an integer representation.
@@ -289,6 +291,7 @@ impl<T> fmt::Debug for PKey<T> {
             Id::DH => "DH",
             Id::EC => "EC",
             Id::ED25519 => "Ed25519",
+            #[cfg(not(feature = "fips"))]
             Id::ED448 => "Ed448",
             _ => "unknown",
         };
diff --git a/boring/src/ssl/mod.rs b/boring/src/ssl/mod.rs
index c3acfabcc..027678b9b 100644
--- a/boring/src/ssl/mod.rs
+++ b/boring/src/ssl/mod.rs
@@ -487,8 +487,10 @@ impl ExtensionType {
     pub const PADDING: Self = Self(ffi::TLSEXT_TYPE_padding as u16);
     pub const EXTENDED_MASTER_SECRET: Self = Self(ffi::TLSEXT_TYPE_extended_master_secret as u16);
     pub const TOKEN_BINDING: Self = Self(ffi::TLSEXT_TYPE_token_binding as u16);
+    #[cfg(not(feature = "fips"))]
     pub const QUIC_TRANSPORT_PARAMETERS_LEGACY: Self =
         Self(ffi::TLSEXT_TYPE_quic_transport_parameters_legacy as u16);
+    #[cfg(not(feature = "fips"))]
     pub const QUIC_TRANSPORT_PARAMETERS_STANDARD: Self =
         Self(ffi::TLSEXT_TYPE_quic_transport_parameters_standard as u16);
     pub const CERT_COMPRESSION: Self = Self(ffi::TLSEXT_TYPE_cert_compression as u16);
@@ -505,8 +507,11 @@ impl ExtensionType {
     pub const KEY_SHARE: Self = Self(ffi::TLSEXT_TYPE_key_share as u16);
     pub const RENEGOTIATE: Self = Self(ffi::TLSEXT_TYPE_renegotiate as u16);
     pub const DELEGATED_CREDENTIAL: Self = Self(ffi::TLSEXT_TYPE_delegated_credential as u16);
+    #[cfg(not(feature = "fips"))]
     pub const APPLICATION_SETTINGS: Self = Self(ffi::TLSEXT_TYPE_application_settings as u16);
+    #[cfg(not(feature = "fips"))]
     pub const ENCRYPTED_CLIENT_HELLO: Self = Self(ffi::TLSEXT_TYPE_encrypted_client_hello as u16);
+    #[cfg(not(feature = "fips"))]
     pub const ECH_IS_INNER: Self = Self(ffi::TLSEXT_TYPE_ech_is_inner as u16);
     pub const CERTIFICATE_TIMESTAMP: Self = Self(ffi::TLSEXT_TYPE_certificate_timestamp as u16);
     pub const NEXT_PROTO_NEG: Self = Self(ffi::TLSEXT_TYPE_next_proto_neg as u16);
diff --git a/boring/src/ssl/test/mod.rs b/boring/src/ssl/test/mod.rs
index abb6b6c82..137411f1e 100644
--- a/boring/src/ssl/test/mod.rs
+++ b/boring/src/ssl/test/mod.rs
@@ -1,6 +1,7 @@
 #![allow(unused_imports)]
 
 use hex;
+use std::cell::Cell;
 use std::env;
 use std::fs::File;
 use std::io::prelude::*;
@@ -508,14 +509,16 @@ fn test_select_cert_error() {
 #[test]
 fn test_select_cert_unknown_extension() {
     let mut server = Server::builder();
-    let unknown_extension = std::sync::Arc::new(std::sync::Mutex::new(None));
+    let unknown_extension = std::sync::Arc::new(std::sync::Mutex::new(Some(vec![])));
 
     server.ctx().set_select_certificate_callback({
         let unknown = unknown_extension.clone();
         move |client_hello| {
-            *unknown.lock().unwrap() = client_hello
-                .get_extension(ExtensionType::QUIC_TRANSPORT_PARAMETERS_LEGACY)
+            let ext = client_hello
+                .get_extension(ExtensionType::SERVER_NAME)
                 .map(ToOwned::to_owned);
+            assert!(ext.is_none());
+            *unknown.lock().unwrap() = ext;
             Ok(())
         }
     });
diff --git a/boring/src/x509/mod.rs b/boring/src/x509/mod.rs
index a02403f46..08f102084 100644
--- a/boring/src/x509/mod.rs
+++ b/boring/src/x509/mod.rs
@@ -197,6 +197,7 @@ impl X509StoreContextRef {
         unsafe { ffi::X509_STORE_CTX_get_error_depth(self.as_ptr()) as u32 }
     }
 
+    #[cfg(not(feature = "fips"))]
     /// Returns a reference to a complete valid `X509` certificate chain.
     ///
     /// This corresponds to [`X509_STORE_CTX_get0_chain`].
@@ -229,12 +230,14 @@ impl X509Builder {
 
     /// Sets the notAfter constraint on the certificate.
     pub fn set_not_after(&mut self, not_after: &Asn1TimeRef) -> Result<(), ErrorStack> {
-        unsafe { cvt(X509_set1_notAfter(self.0.as_ptr(), not_after.as_ptr())).map(|_| ()) }
+        // TODO: once FIPS supports `set1_notAfter`, use that instead
+        unsafe { cvt(X509_set_notAfter(self.0.as_ptr(), not_after.as_ptr())).map(|_| ()) }
     }
 
     /// Sets the notBefore constraint on the certificate.
     pub fn set_not_before(&mut self, not_before: &Asn1TimeRef) -> Result<(), ErrorStack> {
-        unsafe { cvt(X509_set1_notBefore(self.0.as_ptr(), not_before.as_ptr())).map(|_| ()) }
+        // TODO: once FIPS supports `set1_notBefore`, use that instead
+        unsafe { cvt(X509_set_notBefore(self.0.as_ptr(), not_before.as_ptr())).map(|_| ()) }
     }
 
     /// Sets the version of the certificate.
@@ -493,18 +496,18 @@ impl X509Ref {
     /// Returns the certificate's Not After validity period.
     pub fn not_after(&self) -> &Asn1TimeRef {
         unsafe {
-            let date = X509_getm_notAfter(self.as_ptr());
+            let date = X509_get0_notAfter(self.as_ptr());
             assert!(!date.is_null());
-            Asn1TimeRef::from_ptr(date)
+            Asn1TimeRef::from_ptr(date as *mut _)
         }
     }
 
     /// Returns the certificate's Not Before validity period.
     pub fn not_before(&self) -> &Asn1TimeRef {
         unsafe {
-            let date = X509_getm_notBefore(self.as_ptr());
+            let date = X509_get0_notBefore(self.as_ptr());
             assert!(!date.is_null());
-            Asn1TimeRef::from_ptr(date)
+            Asn1TimeRef::from_ptr(date as *mut _)
         }
     }
 
@@ -1160,6 +1163,7 @@ impl X509ReqRef {
         ffi::i2d_X509_REQ
     }
 
+    #[cfg(not(feature = "fips"))]
     /// Returns the numerical value of the version field of the certificate request.
     ///
     /// This corresponds to [`X509_REQ_get_version`]
@@ -1169,6 +1173,7 @@ impl X509ReqRef {
         unsafe { X509_REQ_get_version(self.as_ptr()) as i32 }
     }
 
+    #[cfg(not(feature = "fips"))]
     /// Returns the subject name of the certificate request.
     ///
     /// This corresponds to [`X509_REQ_get_subject_name`]
@@ -1401,14 +1406,12 @@ impl Stackable for X509Object {
     type StackType = ffi::stack_st_X509_OBJECT;
 }
 
-use crate::ffi::{X509_get0_signature, X509_getm_notAfter, X509_getm_notBefore, X509_up_ref};
-
-use crate::ffi::{
-    ASN1_STRING_get0_data, X509_ALGOR_get0, X509_REQ_get_subject_name, X509_REQ_get_version,
-    X509_STORE_CTX_get0_chain, X509_set1_notAfter, X509_set1_notBefore,
-};
+use crate::ffi::{X509_get0_notAfter, X509_get0_notBefore, X509_get0_signature, X509_up_ref};
 
 use crate::ffi::X509_OBJECT_get0_X509;
+use crate::ffi::{ASN1_STRING_get0_data, X509_ALGOR_get0, X509_set_notAfter, X509_set_notBefore};
+#[cfg(not(feature = "fips"))]
+use crate::ffi::{X509_REQ_get_subject_name, X509_REQ_get_version, X509_STORE_CTX_get0_chain};
 
 #[allow(bad_style)]
 unsafe fn X509_OBJECT_free(x: *mut ffi::X509_OBJECT) {
diff --git a/hyper-boring/Cargo.toml b/hyper-boring/Cargo.toml
index 74bce004d..a00d14203 100644
--- a/hyper-boring/Cargo.toml
+++ b/hyper-boring/Cargo.toml
@@ -14,6 +14,7 @@ exclude = ["test/*"]
 default = ["runtime"]
 
 runtime = ["hyper/runtime"]
+fips = ["tokio-boring/fips"]
 
 [dependencies]
 antidote = "1.0.0"
diff --git a/tokio-boring/Cargo.toml b/tokio-boring/Cargo.toml
index 15f6afb5f..9622b6715 100644
--- a/tokio-boring/Cargo.toml
+++ b/tokio-boring/Cargo.toml
@@ -20,3 +20,6 @@ tokio = "1"
 futures = "0.3"
 tokio = { version = "1", features = ["full"] }
 anyhow = "1"
+
+[features]
+fips = ["boring/fips"]