diff --git a/include/gatekeeper/gatekeeper_messages.h b/include/gatekeeper/gatekeeper_messages.h
index 7c4ebf7..1ec1e18 100644
--- a/include/gatekeeper/gatekeeper_messages.h
+++ b/include/gatekeeper/gatekeeper_messages.h
@@ -45,7 +45,7 @@
      * Constructs a SizedBuffer of a provided
      * length.
      */
-    SizedBuffer(uint32_t length) {
+    explicit SizedBuffer(uint32_t length) {
         if (length != 0) {
             buffer.reset(new uint8_t[length]);
         } else {
@@ -75,7 +75,7 @@
  */
 struct GateKeeperMessage {
     GateKeeperMessage() : error(ERROR_NONE) {}
-    GateKeeperMessage(gatekeeper_error_t error) : error(error) {}
+    explicit GateKeeperMessage(gatekeeper_error_t error) : error(error) {}
     virtual ~GateKeeperMessage() {}
 
     /**