diff --git a/mpd/base/content_protection_element.cc b/mpd/base/content_protection_element.cc
new file mode 100644
index 0000000000..8d33af383d
--- /dev/null
+++ b/mpd/base/content_protection_element.cc
@@ -0,0 +1,6 @@
+#include "mpd/base/content_protection_element.h"
+
+namespace dash_packager {
+ContentProtectionElement::ContentProtectionElement() {}
+ContentProtectionElement::~ContentProtectionElement() {}
+}  // namespace dash_packager
diff --git a/mpd/base/content_protection_element.h b/mpd/base/content_protection_element.h
index d80de4a0c1..69f5191e2d 100644
--- a/mpd/base/content_protection_element.h
+++ b/mpd/base/content_protection_element.h
@@ -12,6 +12,9 @@
 namespace dash_packager {
 
 struct ContentProtectionElement {
+  ContentProtectionElement();
+  ~ContentProtectionElement();
+
   std::string value;  // Will be set for 'value' attribute.
   std::string scheme_id_uri;  // Will be set for 'schemeIdUri' attribute.
 
diff --git a/mpd/base/mpd_builder.cc b/mpd/base/mpd_builder.cc
index dbd54a0685..dfd0430144 100644
--- a/mpd/base/mpd_builder.cc
+++ b/mpd/base/mpd_builder.cc
@@ -290,7 +290,7 @@ bool Representation::Init() {
     return false;
   }
 
-  if (!media_info_.container_type() == MediaInfo::CONTAINER_UNKNOWN) {
+  if (media_info_.container_type() == MediaInfo::CONTAINER_UNKNOWN) {
     // TODO(rkuroiwa): This might not be the right behavior. Maybe somehow
     // infer from something else like media file name?
     LOG(ERROR) << "'container_type' in MediaInfo cannot be CONTAINER_UNKNOWN.";
diff --git a/mpd/mpd.gyp b/mpd/mpd.gyp
index 3e6f99b98c..df4f1aaad3 100644
--- a/mpd/mpd.gyp
+++ b/mpd/mpd.gyp
@@ -30,6 +30,7 @@
       'target_name': 'mpd_builder',
       'type': 'static_library',
       'sources': [
+        'base/content_protection_element.cc',
         'base/content_protection_element.h',
         'base/mpd_builder.cc',
         'base/mpd_builder.h',