diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index a7fe69c..f12320d 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -325,7 +325,7 @@
         KeyedVector<int32_t, bool> leds;
         Vector<VirtualKeyDefinition> virtualKeys;
 
-        Device(uint32_t classes) :
+        explicit Device(uint32_t classes) :
                 classes(classes) {
         }
     };