diff --git a/src/arch/aarch64.rs b/src/arch/aarch64.rs
index c8f2b8b..e08d0fc 100644
--- a/src/arch/aarch64.rs
+++ b/src/arch/aarch64.rs
@@ -10,7 +10,6 @@ use core::arch::asm;
 use linux_raw_sys::elf::Elf_Ehdr;
 #[cfg(feature = "take-charge")]
 #[cfg(feature = "signal")]
-#[cfg(test)]
 use linux_raw_sys::general::__NR_rt_sigreturn;
 #[cfg(all(feature = "experimental-relocate", feature = "origin-start"))]
 #[cfg(relocation_model = "pic")]
@@ -275,14 +274,13 @@ pub(super) const TLS_OFFSET: usize = 0;
 #[cfg(feature = "thread")]
 #[inline]
 pub(super) unsafe fn munmap_and_exit_thread(map_addr: *mut c_void, map_len: usize) -> ! {
-    assert_eq!(__NR_exit, 93); // TODO: obviate this
     asm!(
         "svc 0",
         "mov x0, xzr",
-        "mov x8, 93", // TODO: use {__NR_exit}
+        "mov x8, {__NR_exit}",
         "svc 0",
         "udf #16",
-        //__NR_exit = const __NR_exit, // TODO: Use this when `asm_const` is stabilized.
+        __NR_exit = const __NR_exit,
         in("x8") __NR_munmap,
         in("x0") map_addr,
         in("x1") map_len,
@@ -304,16 +302,11 @@ naked_fn!(
     ";
     pub(super) fn return_from_signal_handler() -> ();
 
-    "mov x8, 139", // TODO: use {__NR_rt_sigreturn}
+    "mov x8, {__NR_rt_sigreturn}",
     "svc 0",
     "udf #16";
-    //__NR_rt_sigreturn = const __NR_rt_sigreturn // TODO: Use this when `asm_const` is stabilized.
+    __NR_rt_sigreturn = const __NR_rt_sigreturn
 );
-#[cfg(feature = "take-charge")]
-#[test] // TODO: obviate this
-fn test_rt_sigreturn() {
-    assert_eq!(__NR_rt_sigreturn, 139);
-}
 
 /// Invoke the appropriate system call to return control from a signal
 /// handler that does not use `SA_SIGINFO`. On aarch64, this uses the same
diff --git a/src/arch/arm.rs b/src/arch/arm.rs
index 381b4cb..231c899 100644
--- a/src/arch/arm.rs
+++ b/src/arch/arm.rs
@@ -13,7 +13,6 @@ use linux_raw_sys::elf::Elf_Ehdr;
 use linux_raw_sys::general::{__NR_mprotect, PROT_READ};
 #[cfg(feature = "take-charge")]
 #[cfg(feature = "signal")]
-#[cfg(test)]
 use linux_raw_sys::general::{__NR_rt_sigreturn, __NR_sigreturn};
 #[cfg(feature = "take-charge")]
 #[cfg(feature = "thread")]
@@ -289,14 +288,13 @@ pub(super) const TLS_OFFSET: usize = 0;
 #[cfg(feature = "thread")]
 #[inline]
 pub(super) unsafe fn munmap_and_exit_thread(map_addr: *mut c_void, map_len: usize) -> ! {
-    assert_eq!(__NR_exit, 1); // TODO: obviate this
     asm!(
         "svc 0",
         "mov r0, #0",
-        "mov r7, #1", // TODO: use {__NR_exit}
+        "mov r7, {__NR_exit}",
         "svc 0",
         "udf #16",
-        //__NR_exit = const __NR_exit, // TODO: Use this when `asm_const` is stabilized.
+        __NR_exit = const __NR_exit,
         in("r7") __NR_munmap,
         in("r0") map_addr,
         in("r1") map_len,
@@ -318,16 +316,11 @@ naked_fn!(
     ";
     pub(super) fn return_from_signal_handler() -> ();
 
-    "mov r7, 173", // TODO: use {__NR_rt_sigreturn}
+    "mov r7, {__NR_rt_sigreturn}",
     "swi 0",
     "udf #16";
-    //__NR_rt_sigreturn = const __NR_rt_sigreturn // TODO: Use this when `asm_const` is stabilized.
+    __NR_rt_sigreturn = const __NR_rt_sigreturn
 );
-#[cfg(feature = "take-charge")]
-#[test] // TODO: obviate this
-fn test_rt_sigreturn() {
-    assert_eq!(__NR_rt_sigreturn, 173);
-}
 
 #[cfg(feature = "take-charge")]
 #[cfg(feature = "signal")]
@@ -343,13 +336,8 @@ naked_fn!(
     ";
     pub(super) fn return_from_signal_handler_noinfo() -> ();
 
-    "mov r7, 119", // TODO: use {__NR_sigreturn}
+    "mov r7, {__NR_sigreturn}",
     "swi 0",
     "udf #16";
-    //__NR_sigreturn = const __NR_sigreturn // TODO: Use this when `asm_const` is stabilized.
+    __NR_sigreturn = const __NR_sigreturn
 );
-#[cfg(feature = "take-charge")]
-#[test] // TODO: obviate this
-fn test_sigreturn() {
-    assert_eq!(__NR_sigreturn, 119);
-}
diff --git a/src/arch/riscv64.rs b/src/arch/riscv64.rs
index 9861042..5e53b36 100644
--- a/src/arch/riscv64.rs
+++ b/src/arch/riscv64.rs
@@ -293,14 +293,13 @@ pub(super) const TLS_OFFSET: usize = 0x800;
 #[cfg(feature = "thread")]
 #[inline]
 pub(super) unsafe fn munmap_and_exit_thread(map_addr: *mut c_void, map_len: usize) -> ! {
-    assert_eq!(__NR_exit, 93); // TODO: obviate this
     asm!(
         "ecall",
         "mv a0, zero",
-        "li a7, 93", // TODO: use {__NR_exit}
+        "li a7, {__NR_exit}",
         "ecall",
         "unimp",
-        //__NR_exit = const __NR_exit, // TODO: Use this when `asm_const` is stabilized.
+        __NR_exit = const __NR_exit,
         in("a7") __NR_munmap,
         in("a0") map_addr,
         in("a1") map_len,
diff --git a/src/arch/x86.rs b/src/arch/x86.rs
index ca87456..ba96e6f 100644
--- a/src/arch/x86.rs
+++ b/src/arch/x86.rs
@@ -16,7 +16,6 @@ use linux_raw_sys::elf::Elf_Ehdr;
 use linux_raw_sys::general::{__NR_mprotect, PROT_READ};
 #[cfg(feature = "take-charge")]
 #[cfg(feature = "signal")]
-#[cfg(test)]
 use linux_raw_sys::general::{__NR_rt_sigreturn, __NR_sigreturn};
 #[cfg(feature = "take-charge")]
 #[cfg(feature = "thread")]
@@ -371,16 +370,15 @@ pub(super) const TLS_OFFSET: usize = 0;
 #[cfg(feature = "thread")]
 #[inline]
 pub(super) unsafe fn munmap_and_exit_thread(map_addr: *mut c_void, map_len: usize) -> ! {
-    assert_eq!(__NR_exit, 1); // TODO: obviate this
     asm!(
         // Use `int 0x80` instead of vsyscall, since vsyscall would attempt to
         // touch the stack after we `munmap` it.
         "int 0x80",
         "xor ebx, ebx",
-        "mov eax, 1", // TODO: use {__NR_exit}
+        "mov eax, {__NR_exit}",
         "int 0x80",
         "ud2",
-        //__NR_exit = const __NR_exit, // TODO: Use this when `asm_const` is stabilized.
+        __NR_exit = const __NR_exit,
         in("eax") __NR_munmap,
         in("ebx") map_addr,
         in("ecx") map_len,
@@ -402,17 +400,11 @@ naked_fn!(
     ";
     pub(super) fn return_from_signal_handler() -> ();
 
-    "mov eax, 173", // TODO: use {__NR_rt_sigreturn}
+    "mov eax,  {__NR_rt_sigreturn}",
     "int 0x80",
     "ud2";
-    //__NR_rt_sigreturn = const __NR_rt_sigreturn // TODO: Use this when `asm_const` is stabilized.
+    __NR_rt_sigreturn = const __NR_rt_sigreturn
 );
-#[cfg(feature = "take-charge")]
-#[cfg(feature = "signal")]
-#[test] // TODO: obviate this
-fn test_rt_sigreturn() {
-    assert_eq!(__NR_rt_sigreturn, 173);
-}
 
 #[cfg(feature = "take-charge")]
 #[cfg(feature = "signal")]
@@ -429,14 +421,8 @@ naked_fn!(
     pub(super) fn return_from_signal_handler_noinfo() -> ();
 
     "pop eax",
-    "mov eax, 119", // TODO: use {__NR_sigreturn}
+    "mov eax, {__NR_sigreturn}",
     "int 0x80",
     "ud2";
-    //__NR_sigreturn = const __NR_sigreturn // TODO: Use this when `asm_const` is stabilized.
+    __NR_sigreturn = const __NR_sigreturn
 );
-#[cfg(feature = "take-charge")]
-#[cfg(feature = "signal")]
-#[test] // TODO: obviate this
-fn test_sigreturn() {
-    assert_eq!(__NR_sigreturn, 119);
-}
diff --git a/src/arch/x86_64.rs b/src/arch/x86_64.rs
index 9845450..8a6edca 100644
--- a/src/arch/x86_64.rs
+++ b/src/arch/x86_64.rs
@@ -10,7 +10,6 @@ use core::arch::asm;
 use linux_raw_sys::elf::Elf_Ehdr;
 #[cfg(feature = "take-charge")]
 #[cfg(feature = "signal")]
-#[cfg(test)]
 use linux_raw_sys::general::__NR_rt_sigreturn;
 #[cfg(all(feature = "experimental-relocate", feature = "origin-start"))]
 #[cfg(relocation_model = "pic")]
@@ -283,14 +282,13 @@ pub(super) const TLS_OFFSET: usize = 0;
 #[cfg(feature = "thread")]
 #[inline]
 pub(super) unsafe fn munmap_and_exit_thread(map_addr: *mut c_void, map_len: usize) -> ! {
-    assert_eq!(__NR_exit, 60); // TODO: obviate this
     asm!(
         "syscall",
         "xor edi, edi",
-        "mov eax, 60", // TODO: use {__NR_exit}
+        "mov eax, {__NR_exit}",
         "syscall",
         "ud2",
-        //__NR_exit = const __NR_exit, // TODO: Use this when `asm_const` is stabilized.
+        __NR_exit = const __NR_exit,
         in("rax") __NR_munmap,
         in("rdi") map_addr,
         in("rsi") map_len,
@@ -312,16 +310,11 @@ naked_fn!(
     ";
     pub(super) fn return_from_signal_handler() -> ();
 
-    "mov rax, 15", // TODO: use {__NR_rt_sigreturn}
+    "mov rax, {__NR_rt_sigreturn}",
     "syscall",
     "ud2";
-    //__NR_rt_sigreturn = const __NR_rt_sigreturn // TODO: Use this when `asm_const` is stabilized.
+    __NR_rt_sigreturn = const __NR_rt_sigreturn
 );
-#[cfg(feature = "take-charge")]
-#[test] // TODO: obviate this
-fn test_rt_sigreturn() {
-    assert_eq!(__NR_rt_sigreturn, 15);
-}
 
 /// Invoke the appropriate system call to return control from a signal
 /// handler that does not use `SA_SIGINFO`. On x86-64, this uses the same
diff --git a/tests/abi.rs b/tests/abi.rs
deleted file mode 100644
index 66dd9a5..0000000
--- a/tests/abi.rs
+++ /dev/null
@@ -1,45 +0,0 @@
-//! Test that workarounds for missing `asm_const` have the right values..
-//!
-//! Due to `asm_const` not being stable yet, src/arch/* currently have to
-//! hard-code these ABI magic numbers. Test that the hard-coded numbers
-//! match the upstream numbers.
-//!
-//! Keep these in sync with the code in src/arch/*.
-//!
-//! TODO: When `asm_const` is stable, obviate these tests.
-
-#[cfg(target_arch = "x86")]
-#[test]
-fn test_rt_sigreturn() {
-    assert_eq!(linux_raw_sys::general::__NR_rt_sigreturn, 173);
-}
-
-#[cfg(target_arch = "x86")]
-#[test]
-fn test_sigreturn() {
-    assert_eq!(linux_raw_sys::general::__NR_sigreturn, 119);
-}
-
-#[cfg(target_arch = "aarch64")]
-#[test]
-fn test_rt_sigreturn() {
-    assert_eq!(linux_raw_sys::general::__NR_rt_sigreturn, 139);
-}
-
-#[cfg(target_arch = "arm")]
-#[test]
-fn test_rt_sigreturn() {
-    assert_eq!(linux_raw_sys::general::__NR_rt_sigreturn, 173);
-}
-
-#[cfg(target_arch = "arm")]
-#[test]
-fn test_sigreturn() {
-    assert_eq!(linux_raw_sys::general::__NR_sigreturn, 119);
-}
-
-#[cfg(target_arch = "x86_64")]
-#[test]
-fn test_rt_sigreturn() {
-    assert_eq!(linux_raw_sys::general::__NR_rt_sigreturn, 15);
-}