diff --git a/packager/app/test/testdata/encryption-with-multi-drms/output.mpd b/packager/app/test/testdata/encryption-with-multi-drms/output.mpd
index 4f9bab2413..3815d7834f 100644
--- a/packager/app/test/testdata/encryption-with-multi-drms/output.mpd
+++ b/packager/app/test/testdata/encryption-with-multi-drms/output.mpd
@@ -10,7 +10,7 @@
       <ContentProtection schemeIdUri="urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed">
         <cenc:pssh>AAAAOHBzc2gAAAAA7e+LqXnWSs6jyCfc1R0h7QAAABgSEDEyMzQ1Njc4OTAxMjM0NTZI49yVmwY=</cenc:pssh>
       </ContentProtection>
-      <ContentProtection schemeIdUri="urn:uuid:5e629af5-38da-4063-8977-97ffbd9902d4">
+      <ContentProtection schemeIdUri="urn:uuid:5E629AF5-38DA-4063-8977-97FFBD9902D4">
         <mas:MarlinContentIds>
           <mas:MarlinContentId>urn:marlin:kid:31323334353637383930313233343536</mas:MarlinContentId>
         </mas:MarlinContentIds>
@@ -30,7 +30,7 @@
       <ContentProtection schemeIdUri="urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed">
         <cenc:pssh>AAAAOHBzc2gAAAAA7e+LqXnWSs6jyCfc1R0h7QAAABgSEDEyMzQ1Njc4OTAxMjM0NTZI49yVmwY=</cenc:pssh>
       </ContentProtection>
-      <ContentProtection schemeIdUri="urn:uuid:5e629af5-38da-4063-8977-97ffbd9902d4">
+      <ContentProtection schemeIdUri="urn:uuid:5E629AF5-38DA-4063-8977-97FFBD9902D4">
         <mas:MarlinContentIds>
           <mas:MarlinContentId>urn:marlin:kid:31323334353637383930313233343536</mas:MarlinContentId>
         </mas:MarlinContentIds>
diff --git a/packager/mpd/base/mpd_utils.cc b/packager/mpd/base/mpd_utils.cc
index 9c173413c1..ff3f44a8b4 100644
--- a/packager/mpd/base/mpd_utils.cc
+++ b/packager/mpd/base/mpd_utils.cc
@@ -385,7 +385,6 @@ void AddContentProtectionElementsHelperTemplated(
     }
 
     ContentProtectionElement drm_content_protection;
-    drm_content_protection.scheme_id_uri = "urn:uuid:" + entry.uuid();
 
     if (entry.has_name_version())
       drm_content_protection.value = entry.name_version();
@@ -395,11 +394,17 @@ void AddContentProtectionElementsHelperTemplated(
                  "not support DASH signaling.";
       continue;
     } else if (entry.uuid() == kMarlinUUID) {
+      // Marlin requires its uuid to be in upper case. See #525 for details.
+      drm_content_protection.scheme_id_uri =
+          "urn:uuid:" + base::ToUpperASCII(entry.uuid());
       drm_content_protection.subelements.push_back(
           GenerateMarlinContentIds(protected_content.default_key_id()));
-    } else if (!entry.pssh().empty()) {
-      drm_content_protection.subelements.push_back(
-          GenerateCencPsshElement(entry.pssh()));
+    } else {
+      drm_content_protection.scheme_id_uri = "urn:uuid:" + entry.uuid();
+      if (!entry.pssh().empty()) {
+        drm_content_protection.subelements.push_back(
+            GenerateCencPsshElement(entry.pssh()));
+      }
     }
 
     if (!key_id_uuid_format.empty() && !is_mp4_container) {
diff --git a/packager/mpd/base/mpd_utils_unittest.cc b/packager/mpd/base/mpd_utils_unittest.cc
index b82b8f0a69..37b512508d 100644
--- a/packager/mpd/base/mpd_utils_unittest.cc
+++ b/packager/mpd/base/mpd_utils_unittest.cc
@@ -103,7 +103,7 @@ TEST_F(MpdUtilsTest, ContentProtectionMarlin) {
       "      schemeIdUri='urn:mpeg:dash:mp4protection:2011'"
       "      cenc:default_KID='30313233-3435-3637-3839-3a3b3c3d3e3f'/>"
       "  <ContentProtection"
-      "      schemeIdUri='urn:uuid:5e629af5-38da-4063-8977-97ffbd9902d4'>"
+      "      schemeIdUri='urn:uuid:5E629AF5-38DA-4063-8977-97FFBD9902D4'>"
       "    <mas:MarlinContentIds>"
       "      <mas:MarlinContentId>"
       "        urn:marlin:kid:303132333435363738393a3b3c3d3e3f"