diff --git a/include/remill/Arch/Runtime/Intrinsics.h b/include/remill/Arch/Runtime/Intrinsics.h
index c3f788473..2ccc2ae50 100644
--- a/include/remill/Arch/Runtime/Intrinsics.h
+++ b/include/remill/Arch/Runtime/Intrinsics.h
@@ -59,7 +59,7 @@ __remill_write_memory_64(Memory *, addr_t, uint64_t);
 
 [[gnu::used]] extern float80_t __remill_read_memory_f80(Memory *, addr_t);
 
-[[gnu::used]] extern float64_t __remill_read_memory_f128(Memory *, addr_t);
+[[gnu::used]] extern float128_t __remill_read_memory_f128(Memory *, addr_t);
 
 [[gnu::used, gnu::const]] extern Memory *
 __remill_write_memory_f32(Memory *, addr_t, float32_t);
@@ -71,7 +71,7 @@ __remill_write_memory_f64(Memory *, addr_t, float64_t);
                                                        float80_t);
 
 [[gnu::used]] extern Memory *__remill_write_memory_f128(Memory *, addr_t,
-                                                        float64_t);
+                                                        float128_t);
 
 [[gnu::used, gnu::const]] extern uint8_t __remill_undefined_8(void);
 
@@ -87,6 +87,8 @@ __remill_write_memory_f64(Memory *, addr_t, float64_t);
 
 [[gnu::used, gnu::const]] extern float80_t __remill_undefined_f80(void);
 
+[[gnu::used, gnu::const]] extern float128_t __remill_undefined_f128(void);
+
 // Generic error.
 [[gnu::used]] extern Memory *__remill_error(State &, addr_t addr, Memory *);
 
diff --git a/tests/AArch64/Run.cpp b/tests/AArch64/Run.cpp
index bdd2c9ed6..cd1988083 100644
--- a/tests/AArch64/Run.cpp
+++ b/tests/AArch64/Run.cpp
@@ -143,16 +143,9 @@ MAKE_RW_MEMORY(64)
 
 MAKE_RW_FP_MEMORY(32)
 MAKE_RW_FP_MEMORY(64)
+MAKE_RW_FP_MEMORY(80)
 MAKE_RW_FP_MEMORY(128)
 
-NEVER_INLINE float64_t __remill_read_memory_f80(Memory *, addr_t) {
-  abort();
-}
-
-NEVER_INLINE Memory *__remill_write_memory_f80(Memory *, addr_t, float64_t) {
-  abort();
-}
-
 Memory *__remill_compare_exchange_memory_8(Memory *memory, addr_t addr,
                                            uint8_t &expected, uint8_t desired) {
   expected = __sync_val_compare_and_swap(reinterpret_cast<uint8_t *>(addr),
@@ -338,6 +331,10 @@ float80_t __remill_undefined_f80(void) {
   return {0};
 }
 
+float128_t __remill_undefined_f128(void) {
+  return {0};
+}
+
 // Marks `mem` as being used. This is used for making sure certain symbols are
 // kept around through optimization, and makes sure that optimization doesn't
 // perform dead-argument elimination on any of the intrinsics.
diff --git a/tests/X86/Run.cpp b/tests/X86/Run.cpp
index 6612fa9ea..19fa86388 100644
--- a/tests/X86/Run.cpp
+++ b/tests/X86/Run.cpp
@@ -179,16 +179,7 @@ MAKE_RW_MEMORY(64)
 MAKE_RW_FP_MEMORY(32)
 MAKE_RW_FP_MEMORY(64)
 MAKE_RW_FP_MEMORY(80)
-
-NEVER_INLINE float64_t __remill_read_memory_f128(Memory *, addr_t) {
-  LOG(FATAL) << "Unsupported on x86/amd64";
-  return 0.0;
-}
-
-NEVER_INLINE Memory *__remill_write_memory_f128(Memory *, addr_t, double) {
-  LOG(FATAL) << "Unsupported on x86/amd64";
-  return nullptr;
-}
+MAKE_RW_FP_MEMORY(128)
 
 
 Memory *__remill_compare_exchange_memory_8(Memory *memory, addr_t addr,