diff --git a/runtime/vm/ffi_trampolines_arm64.S b/runtime/vm/ffi_trampolines_arm64.S
index 67aa7192860..db4d4a791b1 100644
--- a/runtime/vm/ffi_trampolines_arm64.S
+++ b/runtime/vm/ffi_trampolines_arm64.S
@@ -144,7 +144,9 @@ _SimulatorFfiCallbackTrampoline:
 SimulatorFfiCallbackTrampoline:
 #endif
 LOCAL_SYMBOL(start):
-#if defined(__APPLE__)
+#if defined(__Fuchsia__)
+  .rept 483 // FfiCallbackMetadata::NumCallbackTrampolinesPerPage()
+#elif defined(__APPLE__)
   .rept 2019 // FfiCallbackMetadata::NumCallbackTrampolinesPerPage()
 #else
   .rept 8163 // FfiCallbackMetadata::NumCallbackTrampolinesPerPage()
@@ -176,7 +178,10 @@ LOCAL_SYMBOL(body):
   mov x1, x9  // I.e., which callback.
 
   adr x2, LOCAL_SYMBOL(start)
-#if defined(__APPLE__)
+#if defined(__Fuchsia__)
+  and x2, x2, ~(0x1000-1)  // FfiCallbackMetadata::kPageSize = 4k
+  add x2, x2, 0x2000
+#elif defined(__APPLE__)
   and x2, x2, ~(0x4000-1)  // FfiCallbackMetadata::kPageSize = 16k
   add x2, x2, 0x8000
 #else
diff --git a/runtime/vm/simulator_arm64.cc b/runtime/vm/simulator_arm64.cc
index fa24636e917..8107d174665 100644
--- a/runtime/vm/simulator_arm64.cc
+++ b/runtime/vm/simulator_arm64.cc
@@ -1834,7 +1834,10 @@ extern "C" void DoRedirectedFfiCallback(CallbackContext* ctxt,
   // Assumptions in ffi_trampolines_arm64.S
   COMPILE_ASSERT(sizeof(CallbackContext) == 144);
   COMPILE_ASSERT(FfiCallbackMetadata::kDoRedirectedFfiCallback == 1);
-#if defined(DART_TARGET_OS_MACOS)
+#if defined(DART_TARGET_OS_FUCHSIA)
+  COMPILE_ASSERT(FfiCallbackMetadata::kPageSize == 4 * KB);
+  COMPILE_ASSERT(FfiCallbackMetadata::NumCallbackTrampolinesPerPage() == 483);
+#elif defined(DART_TARGET_OS_MACOS)
   COMPILE_ASSERT(FfiCallbackMetadata::kPageSize == 16 * KB);
   COMPILE_ASSERT(FfiCallbackMetadata::NumCallbackTrampolinesPerPage() == 2019);
 #else