diff --git a/compiler/rustc_target/src/spec/avr_gnu_base.rs b/compiler/rustc_target/src/spec/avr_gnu_base.rs
index fbec44b716a3ec922d2e3f279627f39a5d6dd38b..cd324c94bbe8b5f14eb0b34e71d587aca5bb2cce 100644
--- a/compiler/rustc_target/src/spec/avr_gnu_base.rs
+++ b/compiler/rustc_target/src/spec/avr_gnu_base.rs
@@ -23,7 +23,7 @@ pub fn target(target_cpu: &'static str, mmcu: &'static str) -> Target {
                 LinkerFlavor::Gnu(Cc::Yes, Lld::No),
                 &["-lgcc"],
             ),
-            max_atomic_width: Some(0),
+            max_atomic_width: Some(16),
             atomic_cas: false,
             relocation_model: RelocModel::Static,
             ..TargetOptions::default()