diff --git a/cmds/dumpstate/DumpstateUtil.h b/cmds/dumpstate/DumpstateUtil.h
index d69ffbf..d75b08c 100644
--- a/cmds/dumpstate/DumpstateUtil.h
+++ b/cmds/dumpstate/DumpstateUtil.h
@@ -76,7 +76,7 @@
   private:
     class CommandOptionsValues {
       private:
-        CommandOptionsValues(int64_t timeout_ms);
+        explicit CommandOptionsValues(int64_t timeout_ms);
 
         int64_t timeout_ms_;
         bool always_;
@@ -88,7 +88,7 @@
         friend class CommandOptionsBuilder;
     };
 
-    CommandOptions(const CommandOptionsValues& values);
+    explicit CommandOptions(const CommandOptionsValues& values);
 
     const CommandOptionsValues values;
 
@@ -119,7 +119,7 @@
         CommandOptions Build();
 
       private:
-        CommandOptionsBuilder(int64_t timeout_ms);
+        explicit CommandOptionsBuilder(int64_t timeout_ms);
         CommandOptionsValues values;
         friend class CommandOptions;
     };
diff --git a/cmds/dumpstate/dumpstate.h b/cmds/dumpstate/dumpstate.h
index ee952d9..7ac25e4 100644
--- a/cmds/dumpstate/dumpstate.h
+++ b/cmds/dumpstate/dumpstate.h
@@ -72,7 +72,7 @@
  */
 class DurationReporter {
   public:
-    DurationReporter(const std::string& title, bool log_only = false);
+    explicit DurationReporter(const std::string& title, bool log_only = false);
 
     ~DurationReporter();
 
@@ -111,7 +111,7 @@
      */
     static const int kDefaultMax;
 
-    Progress(const std::string& path = "");
+    explicit Progress(const std::string& path = "");
 
     // Gets the current progress.
     int32_t Get() const;
@@ -447,7 +447,7 @@
 
   private:
     // Used by GetInstance() only.
-    Dumpstate(const std::string& version = VERSION_CURRENT);
+    explicit Dumpstate(const std::string& version = VERSION_CURRENT);
 
     DISALLOW_COPY_AND_ASSIGN(Dumpstate);
 };
diff --git a/cmds/dumpsys/dumpsys.h b/cmds/dumpsys/dumpsys.h
index 84f3b02..c48a1e9 100644
--- a/cmds/dumpsys/dumpsys.h
+++ b/cmds/dumpsys/dumpsys.h
@@ -26,7 +26,7 @@
 
 class Dumpsys {
   public:
-    Dumpsys(android::IServiceManager* sm) : sm_(sm) {
+    explicit Dumpsys(android::IServiceManager* sm) : sm_(sm) {
     }
     /**
      * Main entry point into dumpsys.