diff --git a/src/util-inl.h b/src/util-inl.h
index 833082291a16aa..864f6d86cdf689 100644
--- a/src/util-inl.h
+++ b/src/util-inl.h
@@ -510,6 +510,22 @@ SlicedArguments::SlicedArguments(
     (*this)[i] = args[i + start];
 }
 
+template <typename T, size_t kStackStorageSize>
+void MaybeStackBuffer<T, kStackStorageSize>::AllocateSufficientStorage(
+    size_t storage) {
+  CHECK(!IsInvalidated());
+  if (storage > capacity()) {
+    bool was_allocated = IsAllocated();
+    T* allocated_ptr = was_allocated ? buf_ : nullptr;
+    buf_ = Realloc(allocated_ptr, storage);
+    capacity_ = storage;
+    if (!was_allocated && length_ > 0)
+      memcpy(buf_, buf_st_, length_ * sizeof(buf_[0]));
+  }
+
+  length_ = storage;
+}
+
 template <typename T, size_t S>
 ArrayBufferViewContents<T, S>::ArrayBufferViewContents(
     v8::Local<v8::Value> value) {
diff --git a/src/util.h b/src/util.h
index 9be4aef5686d3a..ed4bb7dc2dfbd6 100644
--- a/src/util.h
+++ b/src/util.h
@@ -412,19 +412,7 @@ class MaybeStackBuffer {
   // This method can be called multiple times throughout the lifetime of the
   // buffer, but once this has been called Invalidate() cannot be used.
   // Content of the buffer in the range [0, length()) is preserved.
-  void AllocateSufficientStorage(size_t storage) {
-    CHECK(!IsInvalidated());
-    if (storage > capacity()) {
-      bool was_allocated = IsAllocated();
-      T* allocated_ptr = was_allocated ? buf_ : nullptr;
-      buf_ = Realloc(allocated_ptr, storage);
-      capacity_ = storage;
-      if (!was_allocated && length_ > 0)
-        memcpy(buf_, buf_st_, length_ * sizeof(buf_[0]));
-    }
-
-    length_ = storage;
-  }
+  void AllocateSufficientStorage(size_t storage);
 
   void SetLength(size_t length) {
     // capacity() returns how much memory is actually available.