diff --git a/compiler/rustc_target/src/spec/armv4t_none_eabi.rs b/compiler/rustc_target/src/spec/armv4t_none_eabi.rs
index a76ffe808c3b2..797dfe52bd149 100644
--- a/compiler/rustc_target/src/spec/armv4t_none_eabi.rs
+++ b/compiler/rustc_target/src/spec/armv4t_none_eabi.rs
@@ -38,7 +38,9 @@ pub fn target() -> Target {
             linker_flavor: LinkerFlavor::Ld,
             linker: Some("arm-none-eabi-ld".into()),
             asm_args: cvs!["-mthumb-interwork", "-march=armv4t", "-mlittle-endian",],
-            features: "+soft-float,+strict-align".into(),
+            // Force-enable 32-bit atomics, which allows the use of atomic load/store only.
+            // The resulting atomics are ABI incompatible with atomics backed by libatomic.
+            features: "+soft-float,+strict-align,+atomics-32".into(),
             main_needs_argc_argv: false,
             atomic_cas: false,
             has_thumb_interworking: true,
diff --git a/compiler/rustc_target/src/spec/thumbv4t_none_eabi.rs b/compiler/rustc_target/src/spec/thumbv4t_none_eabi.rs
index 7125d141af7f5..bdaaed8b5d0e8 100644
--- a/compiler/rustc_target/src/spec/thumbv4t_none_eabi.rs
+++ b/compiler/rustc_target/src/spec/thumbv4t_none_eabi.rs
@@ -47,7 +47,9 @@ pub fn target() -> Target {
             asm_args: cvs!["-mthumb-interwork", "-march=armv4t", "-mlittle-endian",],
 
             // minimum extra features, these cannot be disabled via -C
-            features: "+soft-float,+strict-align".into(),
+            // Also force-enable 32-bit atomics, which allows the use of atomic load/store only.
+            // The resulting atomics are ABI incompatible with atomics backed by libatomic.
+            features: "+soft-float,+strict-align,+atomics-32".into(),
 
             panic_strategy: PanicStrategy::Abort,
             relocation_model: RelocModel::Static,