diff --git a/src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc b/src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc
index 77d834695..8ecdabd5d 100644
--- a/src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc
+++ b/src/xenia/kernel/xboxkrnl/xboxkrnl_memory.cc
@@ -101,6 +101,9 @@ dword_result_t NtAllocateVirtualMemory(lpdword_t base_addr_ptr,
   if (*base_addr_ptr != 0) {
     // ignore specified page size when base address is specified.
     auto heap = kernel_memory()->LookupHeap(*base_addr_ptr);
+    if (heap->heap_type() != HeapType::kGuestVirtual) {
+      return X_STATUS_INVALID_PARAMETER;
+    }
     page_size = heap->page_size();
   } else {
     // Adjust size.
@@ -192,7 +195,9 @@ dword_result_t NtProtectVirtualMemory(lpdword_t base_addr_ptr,
   }
 
   auto heap = kernel_memory()->LookupHeap(*base_addr_ptr);
-
+  if (heap->heap_type() != HeapType::kGuestVirtual) {
+    return X_STATUS_INVALID_PARAMETER;
+  }
   // Adjust the base downwards to the nearest page boundary.
   uint32_t adjusted_base =
       *base_addr_ptr - (*base_addr_ptr % heap->page_size());
@@ -240,6 +245,9 @@ dword_result_t NtFreeVirtualMemory(lpdword_t base_addr_ptr,
   }
 
   auto heap = kernel_state()->memory()->LookupHeap(base_addr_value);
+  if (heap->heap_type() != HeapType::kGuestVirtual) {
+    return X_STATUS_INVALID_PARAMETER;
+  }
   bool result = false;
   if (free_type == X_MEM_DECOMMIT) {
     // If zero, we may need to query size (free whole region).