diff --git a/Cargo.lock b/Cargo.lock
index 9b02294d4..abae724e5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6995,6 +6995,18 @@ dependencies = [
  "stm32h7",
 ]
 
+[[package]]
+name = "tests-grapefruit"
+version = "0.1.0"
+dependencies = [
+ "build-util",
+ "cfg-if",
+ "cortex-m",
+ "cortex-m-rt",
+ "kern",
+ "stm32h7",
+]
+
 [[package]]
 name = "tests-lpc55xpresso"
 version = "0.1.0"
diff --git a/build/xtask/src/config.rs b/build/xtask/src/config.rs
index cbea48452..0aff68a20 100644
--- a/build/xtask/src/config.rs
+++ b/build/xtask/src/config.rs
@@ -879,7 +879,7 @@ impl BuildConfig<'_> {
 
         let mut nightly_features = vec![];
         // nightly features that we use:
-        nightly_features.extend(["emit_stack_sizes", "used_with_arg"]);
+        nightly_features.extend(["emit_stack_sizes"]);
         // nightly features that our dependencies use:
         nightly_features.extend([
             "backtrace",
diff --git a/test/test-suite/src/main.rs b/test/test-suite/src/main.rs
index 8cf93854b..81b802545 100644
--- a/test/test-suite/src/main.rs
+++ b/test/test-suite/src/main.rs
@@ -18,7 +18,6 @@
 //!
 //! The Idol server, `test-idol-server`, tests Idol-mediated IPC.  It must be
 //! included in the image with the name `idol`, but its ID is immaterial.
-#![feature(used_with_arg)]
 #![no_std]
 #![no_main]
 #![forbid(clippy::wildcard_imports)]
@@ -47,15 +46,14 @@ ringbuf!(Trace, 64, Trace::None);
 /// secure fault, and a different constant will be required.)
 const BAD_ADDRESS: u32 = 0x0;
 
-/// Helper macro for building a list of functions with their names.
-/// We use the humility debug processing to get the name of each
-/// test case and the total number of tests. The #[used(linker)]
-/// is to ensure that this actually gets emitted as a symbol.
+/// Helper macro for building a list of functions with their names. We use the
+/// humility debug processing to get the name of each test case and the total
+/// number of tests. The `unsafe(no_mangle)` and `pub static mut` are to ensure
+/// that this actually gets emitted as a symbol.
 macro_rules! test_cases {
     ($($(#[$attr:meta])* $name:path,)*) => {
         #[unsafe(no_mangle)]
-        #[used(linker)]
-        static TESTS: &[(&str, &(dyn Fn() + Send + Sync))] = &[
+        pub static mut TESTS: &[(&str, &(dyn Fn() + Send + Sync))] = &[
             $(
                 $(#[$attr])*
                 (stringify!($name), &$name)
@@ -1683,7 +1681,12 @@ fn main() -> ! {
                         caller.reply(());
                         ringbuf_entry!(Trace::TestStart);
 
-                        TESTS[idx].1();
+                        // SAFETY: this is single-threaded code.  In addition,
+                        // `TESTS` is only `pub static mut` to ensure that it's
+                        // compiled into the binary; no one mutates it.
+                        unsafe {
+                            TESTS[idx].1();
+                        }
 
                         let op = RunnerOp::TestComplete as u16;
 
diff --git a/test/tests-grapefruit/Cargo.toml b/test/tests-grapefruit/Cargo.toml
new file mode 100644
index 000000000..c6e978917
--- /dev/null
+++ b/test/tests-grapefruit/Cargo.toml
@@ -0,0 +1,28 @@
+[package]
+edition = "2024"
+name = "tests-grapefruit"
+version = "0.1.0"
+
+[features]
+h753 = ["stm32h7/stm32h753"]
+
+[dependencies]
+cfg-if = { workspace = true }
+cortex-m = { workspace = true }
+cortex-m-rt = { workspace = true }
+stm32h7 = { workspace = true, features = ["rt"] }
+
+kern = { path = "../../sys/kern" }
+
+[build-dependencies]
+build-util = { path = "../../build/util" }
+
+[[bin]]
+name = "tests-grapefruit"
+path = "../../app/grapefruit/src/main.rs"
+test = false
+doctest = false
+bench = false
+
+[lints]
+workspace = true
diff --git a/test/tests-grapefruit/app.toml b/test/tests-grapefruit/app.toml
new file mode 100644
index 000000000..1cb217991
--- /dev/null
+++ b/test/tests-grapefruit/app.toml
@@ -0,0 +1,65 @@
+name = "tests-grapefruit"
+target = "thumbv7em-none-eabihf"
+board = "grapefruit-a"
+chip = "../../chips/stm32h7"
+default-ram = "dtcm"
+stacksize = 2048
+
+[kernel]
+name = "grapefruit"
+requires = {flash = 32768, ram = 4096}
+
+[tasks.runner]
+name = "test-runner"
+priority = 0
+max-sizes = {flash = 16384, ram = 4096}
+start = true
+
+[tasks.suite]
+name = "test-suite"
+priority = 2
+max-sizes = {flash = 65536, ram = 4096}
+start = true
+task-slots = ["assist", "idol", "suite", "runner"]# this doesn't actually use SPI; we're just mapping that interrupt to test
+# interrupt handling. chosen completely arbitrarily.
+uses = ["spi1"]
+notifications = ["test-irq"]
+interrupts = {"spi1.irq" = "test-irq"}
+
+# This block is used to test the task_config macro
+[tasks.suite.config]
+foo = '"Hello, world"'
+bar = 42
+baz = [1, 2, 3, 4]
+tup = [[1, true], [2, true], [3, false]]
+
+[tasks.assist]
+name = "test-assist"
+priority = 1
+max-sizes = {flash = 16384, ram = 4096}
+start = true
+
+[tasks.idol]
+name = "test-idol-server"
+priority = 1
+max-sizes = {flash = 4096, ram = 1024}
+stacksize = 1024
+start = true
+
+[tasks.hiffy]
+name = "task-hiffy"
+priority = 3
+features = ["testsuite"]
+max-sizes = {flash = 32768, ram = 16384 }
+stacksize = 2048
+start = true
+task-slots = ["suite", "runner"]
+notifications = ["timer"]
+
+[tasks.idle]
+name = "task-idle"
+priority = 4
+max-sizes = {flash = 256, ram = 256}
+stacksize = 256
+start = true
+