diff --git a/library/compiler-builtins/build.rs b/library/compiler-builtins/build.rs
index 1b901b7e8fab..44946c1240c9 100644
--- a/library/compiler-builtins/build.rs
+++ b/library/compiler-builtins/build.rs
@@ -461,7 +461,7 @@ mod c {
             ]);
         }
 
-        if target_arch == "aarch64" && consider_float_intrinsics {
+        if (target_arch == "aarch64" || target_arch == "arm64ec") && consider_float_intrinsics {
             sources.extend(&[
                 ("__comparetf2", "comparetf2.c"),
                 ("__extenddftf2", "extenddftf2.c"),
diff --git a/library/compiler-builtins/src/lib.rs b/library/compiler-builtins/src/lib.rs
index 66540bb9b6bd..a414efde0ce9 100644
--- a/library/compiler-builtins/src/lib.rs
+++ b/library/compiler-builtins/src/lib.rs
@@ -59,7 +59,7 @@ pub mod mem;
 #[cfg(target_arch = "arm")]
 pub mod arm;
 
-#[cfg(target_arch = "aarch64")]
+#[cfg(any(target_arch = "aarch64", target_arch = "arm64ec"))]
 pub mod aarch64;
 
 #[cfg(all(target_arch = "aarch64", target_os = "linux", not(feature = "no-asm"),))]
diff --git a/library/compiler-builtins/testcrate/tests/lse.rs b/library/compiler-builtins/testcrate/tests/lse.rs
index 5589f22f1e93..63c98957cf4f 100644
--- a/library/compiler-builtins/testcrate/tests/lse.rs
+++ b/library/compiler-builtins/testcrate/tests/lse.rs
@@ -1,5 +1,8 @@
 #![feature(decl_macro)] // so we can use pub(super)
-#![cfg(all(target_arch = "aarch64", not(feature = "no-asm")))]
+#![cfg(all(
+    any(target_arch = "aarch64", target_arch = "arm64ec"),
+    not(feature = "no-asm")
+))]
 
 /// Translate a byte size to a Rust type.
 macro int_ty {