diff --git a/libutils/include/utils/String16.h b/libutils/include/utils/String16.h
index 013705b0e..1a4b47eef 100644
--- a/libutils/include/utils/String16.h
+++ b/libutils/include/utils/String16.h
@@ -187,7 +187,7 @@ public:
 ANDROID_TRIVIAL_MOVE_TRAIT(String16)
 
 static inline std::ostream& operator<<(std::ostream& os, const String16& str) {
-    os << String8(str).c_str();
+    os << String8(str);
     return os;
 }
 
diff --git a/libutils/include/utils/String8.h b/libutils/include/utils/String8.h
index d0ad31464..0bcb716af 100644
--- a/libutils/include/utils/String8.h
+++ b/libutils/include/utils/String8.h
@@ -17,7 +17,8 @@
 #ifndef ANDROID_STRING8_H
 #define ANDROID_STRING8_H
 
-#include <string> // for std::string
+#include <iostream>
+#include <string>
 
 #include <utils/Errors.h>
 #include <utils/Unicode.h>
@@ -232,6 +233,11 @@ private:
 // require any change to the underlying SharedBuffer contents or reference count.
 ANDROID_TRIVIAL_MOVE_TRAIT(String8)
 
+static inline std::ostream& operator<<(std::ostream& os, const String8& str) {
+    os << str.c_str();
+    return os;
+}
+
 // ---------------------------------------------------------------------------
 // No user servicable parts below.