diff --git a/libwvdrmengine/cdm/core/test/certificate_provisioning_unittest.cpp b/libwvdrmengine/cdm/core/test/certificate_provisioning_unittest.cpp
index 01328861..fcc62117 100644
--- a/libwvdrmengine/cdm/core/test/certificate_provisioning_unittest.cpp
+++ b/libwvdrmengine/cdm/core/test/certificate_provisioning_unittest.cpp
@@ -131,6 +131,7 @@ namespace wvcdm {
 using ::testing::_;
 using ::testing::ByMove;
 using ::testing::DoAll;
+using ::testing::HasSubstr;
 using ::testing::NiceMock;
 using ::testing::NotNull;
 using ::testing::Return;
@@ -468,7 +469,7 @@ TEST_P(CertificateProvisioningTest, ProvisioningResponseSuccess) {
       .WillOnce(DoAll(SaveArg<0>(&stored_certificate), ReturnArg<1>()));
 
   MockFileSystem file_system;
-  EXPECT_CALL(file_system, Open(StrEq(wvutil::kLegacyCertificateFileName), _))
+  EXPECT_CALL(file_system, Open(HasSubstr(wvutil::kLegacyCertificateFileName), _))
       .Times(1)
       .WillOnce(Return(ByMove(std::unique_ptr<File>(file))));