diff --git a/runtime/cpp/emboss_array_view.h b/runtime/cpp/emboss_array_view.h
index a1544c6..79c6268 100644
--- a/runtime/cpp/emboss_array_view.h
+++ b/runtime/cpp/emboss_array_view.h
@@ -338,6 +338,10 @@
                            kAddressableUnitSize> *array,
     Stream *stream, const TextOutputOptions &options) {
   // Intentionally empty.  Overload for specific element types.
+  // Avoid unused parameters error:
+  static_cast<void>(array);
+  static_cast<void>(stream);
+  static_cast<void>(options);
 }
 
 // Prints out the elements of an 8-bit Int or UInt array as characters.
diff --git a/runtime/cpp/emboss_prelude.h b/runtime/cpp/emboss_prelude.h
index 463f0fa..a47b8b5 100644
--- a/runtime/cpp/emboss_prelude.h
+++ b/runtime/cpp/emboss_prelude.h
@@ -752,7 +752,11 @@
     buffer_.WriteUInt(ConvertToUInt(value));
     return true;
   }
-  static constexpr bool CouldWriteValue(ValueType value) { return true; }
+  static constexpr bool CouldWriteValue(ValueType value) {
+    // Avoid unused parameters error:
+    static_cast<void>(value);
+    return true;
+  }
   void UncheckedWrite(ValueType value) const {
     buffer_.UncheckedWriteUInt(ConvertToUInt(value));
   }