1 files changed, 4 insertions, 1 deletions
diff --git a/src/core/hle/kernel/vm_manager.cpp b/src/core/hle/kernel/vm_manager.cpp
index 721f7cc44..6b2d78cc8 100644
--- a/src/core/hle/kernel/vm_manager.cpp
+++ b/src/core/hle/kernel/vm_manager.cpp
@@ -765,11 +765,14 @@ void VMManager::MergeAdjacentVMA(VirtualMemoryArea& left, const VirtualMemoryAre
             // Fast case: left is an entire backing block.
             left.backing_block->insert(left.backing_block->end(), right_begin, right_end);
         } else {
+            // Slow case: make a new memory block for left and right.
             const auto left_begin = left.backing_block->begin() + left.offset;
             const auto left_end = left_begin + left.size;
+            const auto left_size = static_cast<std::size_t>(std::distance(left_begin, left_end));
+            const auto right_size = static_cast<std::size_t>(std::distance(right_begin, right_end));
 
-            // Slow case: make a new memory block for left and right.
             auto new_memory = std::make_shared<PhysicalMemory>();
+            new_memory->reserve(left_size + right_size);
             new_memory->insert(new_memory->end(), left_begin, left_end);
             new_memory->insert(new_memory->end(), right_begin, right_end);