diff --git a/libwvdrmengine/cdm/core/src/entitlement_key_session.cpp b/libwvdrmengine/cdm/core/src/entitlement_key_session.cpp
index 8adc5b68..b52ee22a 100644
--- a/libwvdrmengine/cdm/core/src/entitlement_key_session.cpp
+++ b/libwvdrmengine/cdm/core/src/entitlement_key_session.cpp
@@ -10,7 +10,7 @@
 
 namespace wvcdm {
 namespace {
-constexpr int kInvalidKeySessionId = 0;
+constexpr uint32_t kInvalidKeySessionId = 0xFFFFFFFF;
 }  // namespace
 
 EntitlementKeySession::EntitlementKeySession(