diff --git a/library/std/build.rs b/library/std/build.rs
index 83073cc77dd1a..04bfed12153ec 100644
--- a/library/std/build.rs
+++ b/library/std/build.rs
@@ -16,6 +16,9 @@ fn main() {
     } else if target.contains("freebsd") {
         println!("cargo:rustc-link-lib=execinfo");
         println!("cargo:rustc-link-lib=pthread");
+        if env::var("RUST_STD_FREEBSD_12_ABI").is_ok() {
+            println!("cargo:rustc-cfg=freebsd12");
+        }
     } else if target.contains("netbsd") {
         println!("cargo:rustc-link-lib=pthread");
         println!("cargo:rustc-link-lib=rt");
diff --git a/library/std/src/os/freebsd/fs.rs b/library/std/src/os/freebsd/fs.rs
index c6a00e179bd7f..1eda8690d5d1b 100644
--- a/library/std/src/os/freebsd/fs.rs
+++ b/library/std/src/os/freebsd/fs.rs
@@ -74,7 +74,14 @@ pub trait MetadataExt {
 impl MetadataExt for Metadata {
     #[allow(deprecated)]
     fn as_raw_stat(&self) -> &raw::stat {
-        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+        // The methods below use libc::stat, so they work fine when libc is built with FreeBSD 12 ABI.
+        // This method would just return nonsense.
+        #[cfg(freebsd12)]
+        panic!("as_raw_stat not supported with FreeBSD 12 ABI");
+        #[cfg(not(freebsd12))]
+        unsafe {
+            &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat)
+        }
     }
     fn st_dev(&self) -> u64 {
         self.as_inner().as_inner().st_dev as u64
@@ -136,6 +143,11 @@ impl MetadataExt for Metadata {
     fn st_flags(&self) -> u32 {
         self.as_inner().as_inner().st_flags as u32
     }
+    #[cfg(freebsd12)]
+    fn st_lspare(&self) -> u32 {
+        panic!("st_lspare not supported with FreeBSD 12 ABI");
+    }
+    #[cfg(not(freebsd12))]
     fn st_lspare(&self) -> u32 {
         self.as_inner().as_inner().st_lspare as u32
     }
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index 7d9b442e6468b..f1bc3d11d8b77 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -794,6 +794,7 @@ fn supported_sanitizers(
         }
         "x86_64-apple-darwin" => darwin_libs("osx", &["asan", "lsan", "tsan"]),
         "x86_64-fuchsia" => common_libs("fuchsia", "x86_64", &["asan"]),
+        "x86_64-unknown-freebsd" => common_libs("freebsd", "x86_64", &["asan", "msan", "tsan"]),
         "x86_64-unknown-linux-gnu" => {
             common_libs("linux", "x86_64", &["asan", "lsan", "msan", "tsan"])
         }
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
index 766e6531c9507..bfc768f993512 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
@@ -29,5 +29,5 @@ ENV \
 
 ENV HOSTS=x86_64-unknown-freebsd
 
-ENV RUST_CONFIGURE_ARGS --enable-extended --enable-profiler --disable-docs
+ENV RUST_CONFIGURE_ARGS --enable-extended --enable-profiler --enable-sanitizers --disable-docs
 ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $HOSTS
diff --git a/src/librustc_codegen_ssa/back/link.rs b/src/librustc_codegen_ssa/back/link.rs
index 5de7ffbcfcbfb..bfcf979d12548 100644
--- a/src/librustc_codegen_ssa/back/link.rs
+++ b/src/librustc_codegen_ssa/back/link.rs
@@ -822,6 +822,7 @@ fn link_sanitizer_runtime(sess: &Session, linker: &mut dyn Linker, name: &str) {
         "aarch64-fuchsia"
         | "aarch64-unknown-linux-gnu"
         | "x86_64-fuchsia"
+        | "x86_64-unknown-freebsd"
         | "x86_64-unknown-linux-gnu" => {
             let filename = format!("librustc{}_rt.{}.a", channel, name);
             let path = default_tlib.join(&filename);
diff --git a/src/librustc_session/session.rs b/src/librustc_session/session.rs
index 9191f7e8d76be..66dbe53bac387 100644
--- a/src/librustc_session/session.rs
+++ b/src/librustc_session/session.rs
@@ -1453,14 +1453,19 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
         "aarch64-unknown-linux-gnu",
         "x86_64-apple-darwin",
         "x86_64-fuchsia",
+        "x86_64-unknown-freebsd",
         "x86_64-unknown-linux-gnu",
     ];
     const LSAN_SUPPORTED_TARGETS: &[&str] =
         &["aarch64-unknown-linux-gnu", "x86_64-apple-darwin", "x86_64-unknown-linux-gnu"];
     const MSAN_SUPPORTED_TARGETS: &[&str] =
-        &["aarch64-unknown-linux-gnu", "x86_64-unknown-linux-gnu"];
-    const TSAN_SUPPORTED_TARGETS: &[&str] =
-        &["aarch64-unknown-linux-gnu", "x86_64-apple-darwin", "x86_64-unknown-linux-gnu"];
+        &["aarch64-unknown-linux-gnu", "x86_64-unknown-freebsd", "x86_64-unknown-linux-gnu"];
+    const TSAN_SUPPORTED_TARGETS: &[&str] = &[
+        "aarch64-unknown-linux-gnu",
+        "x86_64-apple-darwin",
+        "x86_64-unknown-freebsd",
+        "x86_64-unknown-linux-gnu",
+    ];
 
     // Sanitizers can only be used on some tested platforms.
     for s in sess.opts.debugging_opts.sanitizer {
diff --git a/src/tools/compiletest/src/util.rs b/src/tools/compiletest/src/util.rs
index ddd7941b11469..a776bb0bfe481 100644
--- a/src/tools/compiletest/src/util.rs
+++ b/src/tools/compiletest/src/util.rs
@@ -87,6 +87,7 @@ pub const ASAN_SUPPORTED_TARGETS: &'static [&'static str] = &[
     "aarch64-unknown-linux-gnu",
     "x86_64-apple-darwin",
     "x86_64-fuchsia",
+    "x86_64-unknown-freebsd",
     "x86_64-unknown-linux-gnu",
 ];
 
@@ -94,10 +95,14 @@ pub const LSAN_SUPPORTED_TARGETS: &'static [&'static str] =
     &["aarch64-unknown-linux-gnu", "x86_64-apple-darwin", "x86_64-unknown-linux-gnu"];
 
 pub const MSAN_SUPPORTED_TARGETS: &'static [&'static str] =
-    &["aarch64-unknown-linux-gnu", "x86_64-unknown-linux-gnu"];
+    &["aarch64-unknown-linux-gnu", "x86_64-unknown-freebsd", "x86_64-unknown-linux-gnu"];
 
-pub const TSAN_SUPPORTED_TARGETS: &'static [&'static str] =
-    &["aarch64-unknown-linux-gnu", "x86_64-apple-darwin", "x86_64-unknown-linux-gnu"];
+pub const TSAN_SUPPORTED_TARGETS: &'static [&'static str] = &[
+    "aarch64-unknown-linux-gnu",
+    "x86_64-apple-darwin",
+    "x86_64-unknown-freebsd",
+    "x86_64-unknown-linux-gnu",
+];
 
 const BIG_ENDIAN: &'static [&'static str] = &[
     "armebv7r",