diff --git a/src/passes/Asyncify.cpp b/src/passes/Asyncify.cpp
index 7ac9cf48921..994142e482f 100644
--- a/src/passes/Asyncify.cpp
+++ b/src/passes/Asyncify.cpp
@@ -244,6 +244,10 @@
 //      Logs out instrumentation decisions to the console. This can help figure
 //      out why a certain function was instrumented.
 //
+//   --pass-arg=asyncify-memory@memory
+//      Picks which exported memory of the module to store and load data from
+//      and to (useful if the module contains multiple memories).
+//
 // For manual fine-tuning of the list of instrumented functions, there are lists
 // that you can set. These must be used carefully, as misuse can break your
 // application - for example, if a function is called that should be
@@ -1648,14 +1652,31 @@ struct Asyncify : public Pass {
     auto propagateAddList = hasArgument("asyncify-propagate-addlist");
 
     // Ensure there is a memory, as we need it.
+
     if (secondaryMemory) {
       auto secondaryMemorySizeString =
         getArgumentOrDefault("asyncify-secondary-memory-size", "1");
       Address secondaryMemorySize = std::stoi(secondaryMemorySizeString);
       asyncifyMemory = createSecondaryMemory(module, secondaryMemorySize);
     } else {
-      MemoryUtils::ensureExists(module);
-      asyncifyMemory = module->memories[0]->name;
+      if (module->memories.size() <= 1) {
+        MemoryUtils::ensureExists(module);
+        asyncifyMemory = module->memories[0]->name;
+      } else {
+        auto asyncifyMemoryValue =
+          getArgumentOrDefault("asyncify-memory", "memory");
+        for (auto& theExport : module->exports) {
+          if (theExport->kind == ExternalKind::Memory &&
+              theExport->name == asyncifyMemoryValue) {
+            asyncifyMemory = theExport->value;
+            break;
+          }
+        }
+        if (!asyncifyMemory) {
+          Fatal() << "Please specify which of the multiple memories to use, "
+                     "with --pass-arg=asyncify-memory@memory";
+        }
+      }
     }
     pointerType =
       module->getMemory(asyncifyMemory)->is64() ? Type::i64 : Type::i32;
diff --git a/test/lit/passes/asyncify_pass-arg=asyncify-memory@memory.wast b/test/lit/passes/asyncify_pass-arg=asyncify-memory@memory.wast
new file mode 100644
index 00000000000..86bc1d10aba
--- /dev/null
+++ b/test/lit/passes/asyncify_pass-arg=asyncify-memory@memory.wast
@@ -0,0 +1,124 @@
+;; NOTE: Assertions have been generated by update_lit_checks.py --all-items and should not be edited.
+
+;; RUN: foreach %s %t wasm-opt --enable-multimemory --enable-mutable-globals --asyncify --pass-arg=asyncify-memory@memory -S -o - | filecheck %s
+
+;; This test checks that the asyncify-memory argument can pick which memory to use in asyncify.
+(module
+  ;; CHECK:      (type $0 (func (param i32)))
+
+  ;; CHECK:      (type $1 (func))
+
+  ;; CHECK:      (type $2 (func (result i32)))
+
+  ;; CHECK:      (global $__asyncify_state (mut i32) (i32.const 0))
+
+  ;; CHECK:      (global $__asyncify_data (mut i32) (i32.const 0))
+
+  ;; CHECK:      (memory $unused0 1 1)
+  (memory $unused0 (export "unused0") 1 1)
+  ;; CHECK:      (memory $mem 1 1)
+  (memory $mem (export "memory") 1 1)
+  ;; CHECK:      (memory $ignore 1 1)
+  (memory $ignore (export "unused") 1 1)
+)
+;; CHECK:      (export "unused0" (memory $unused0))
+
+;; CHECK:      (export "memory" (memory $mem))
+
+;; CHECK:      (export "unused" (memory $ignore))
+
+;; CHECK:      (export "asyncify_start_unwind" (func $asyncify_start_unwind))
+
+;; CHECK:      (export "asyncify_stop_unwind" (func $asyncify_stop_unwind))
+
+;; CHECK:      (export "asyncify_start_rewind" (func $asyncify_start_rewind))
+
+;; CHECK:      (export "asyncify_stop_rewind" (func $asyncify_stop_rewind))
+
+;; CHECK:      (export "asyncify_get_state" (func $asyncify_get_state))
+
+;; CHECK:      (func $asyncify_start_unwind (param $0 i32)
+;; CHECK-NEXT:  (global.set $__asyncify_state
+;; CHECK-NEXT:   (i32.const 1)
+;; CHECK-NEXT:  )
+;; CHECK-NEXT:  (global.set $__asyncify_data
+;; CHECK-NEXT:   (local.get $0)
+;; CHECK-NEXT:  )
+;; CHECK-NEXT:  (if
+;; CHECK-NEXT:   (i32.gt_u
+;; CHECK-NEXT:    (i32.load $mem
+;; CHECK-NEXT:     (global.get $__asyncify_data)
+;; CHECK-NEXT:    )
+;; CHECK-NEXT:    (i32.load $mem offset=4
+;; CHECK-NEXT:     (global.get $__asyncify_data)
+;; CHECK-NEXT:    )
+;; CHECK-NEXT:   )
+;; CHECK-NEXT:   (then
+;; CHECK-NEXT:    (unreachable)
+;; CHECK-NEXT:   )
+;; CHECK-NEXT:  )
+;; CHECK-NEXT: )
+
+;; CHECK:      (func $asyncify_stop_unwind
+;; CHECK-NEXT:  (global.set $__asyncify_state
+;; CHECK-NEXT:   (i32.const 0)
+;; CHECK-NEXT:  )
+;; CHECK-NEXT:  (if
+;; CHECK-NEXT:   (i32.gt_u
+;; CHECK-NEXT:    (i32.load $mem
+;; CHECK-NEXT:     (global.get $__asyncify_data)
+;; CHECK-NEXT:    )
+;; CHECK-NEXT:    (i32.load $mem offset=4
+;; CHECK-NEXT:     (global.get $__asyncify_data)
+;; CHECK-NEXT:    )
+;; CHECK-NEXT:   )
+;; CHECK-NEXT:   (then
+;; CHECK-NEXT:    (unreachable)
+;; CHECK-NEXT:   )
+;; CHECK-NEXT:  )
+;; CHECK-NEXT: )
+
+;; CHECK:      (func $asyncify_start_rewind (param $0 i32)
+;; CHECK-NEXT:  (global.set $__asyncify_state
+;; CHECK-NEXT:   (i32.const 2)
+;; CHECK-NEXT:  )
+;; CHECK-NEXT:  (global.set $__asyncify_data
+;; CHECK-NEXT:   (local.get $0)
+;; CHECK-NEXT:  )
+;; CHECK-NEXT:  (if
+;; CHECK-NEXT:   (i32.gt_u
+;; CHECK-NEXT:    (i32.load $mem
+;; CHECK-NEXT:     (global.get $__asyncify_data)
+;; CHECK-NEXT:    )
+;; CHECK-NEXT:    (i32.load $mem offset=4
+;; CHECK-NEXT:     (global.get $__asyncify_data)
+;; CHECK-NEXT:    )
+;; CHECK-NEXT:   )
+;; CHECK-NEXT:   (then
+;; CHECK-NEXT:    (unreachable)
+;; CHECK-NEXT:   )
+;; CHECK-NEXT:  )
+;; CHECK-NEXT: )
+
+;; CHECK:      (func $asyncify_stop_rewind
+;; CHECK-NEXT:  (global.set $__asyncify_state
+;; CHECK-NEXT:   (i32.const 0)
+;; CHECK-NEXT:  )
+;; CHECK-NEXT:  (if
+;; CHECK-NEXT:   (i32.gt_u
+;; CHECK-NEXT:    (i32.load $mem
+;; CHECK-NEXT:     (global.get $__asyncify_data)
+;; CHECK-NEXT:    )
+;; CHECK-NEXT:    (i32.load $mem offset=4
+;; CHECK-NEXT:     (global.get $__asyncify_data)
+;; CHECK-NEXT:    )
+;; CHECK-NEXT:   )
+;; CHECK-NEXT:   (then
+;; CHECK-NEXT:    (unreachable)
+;; CHECK-NEXT:   )
+;; CHECK-NEXT:  )
+;; CHECK-NEXT: )
+
+;; CHECK:      (func $asyncify_get_state (result i32)
+;; CHECK-NEXT:  (global.get $__asyncify_state)
+;; CHECK-NEXT: )