diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc
index d63fed5..73574ba 100644
--- a/compiler/image_writer.cc
+++ b/compiler/image_writer.cc
@@ -859,7 +859,7 @@
     return true;
   }
 
-  mutable std::unordered_set<mirror::Class*> classes_to_prune_;
+  std::unordered_set<mirror::Class*> classes_to_prune_;
   ImageWriter* const image_writer_;
 };
 
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 777786c..c80f91a 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -1290,8 +1290,11 @@
           // the app image.
           klass->SetClassLoader(class_loader.Get());
           // The resolved type could be from another dex cache, go through the dex cache just in
-          // case.
-          klass->SetDexCacheStrings(klass->GetDexCache()->GetStrings());
+          // case. May be null for array classes.
+          if (klass->GetDexCacheStrings() != nullptr) {
+            DCHECK(!klass->IsArrayClass());
+            klass->SetDexCacheStrings(klass->GetDexCache()->GetStrings());
+          }
           // If there are multiple dex caches, there may be the same class multiple times
           // in different dex caches. Check for this since inserting will add duplicates
           // otherwise.
diff --git a/runtime/jit/jit.cc b/runtime/jit/jit.cc
index b711181..fa5c41d 100644
--- a/runtime/jit/jit.cc
+++ b/runtime/jit/jit.cc
@@ -243,7 +243,7 @@
       classes_.push_back(klass);
       return true;
     }
-    mutable std::vector<mirror::Class*> classes_;
+    std::vector<mirror::Class*> classes_;
   };
 
   if (generate_debug_info_) {