diff --git a/tests/lib/cpp/cxx/testcase.yaml b/tests/lib/cpp/cxx/testcase.yaml
index 30d4acc6f88..5601886b150 100644
--- a/tests/lib/cpp/cxx/testcase.yaml
+++ b/tests/lib/cpp/cxx/testcase.yaml
@@ -39,6 +39,7 @@ tests:
     platform_exclude:
       - nrf54l15pdk/nrf54l15/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l20pdk/nrf54l20/cpuapp
       - nrf54h20dk/nrf54h20/cpuapp
       - nrf54h20dk/nrf54h20/cpurad
       - nrf9280pdk/nrf9280/cpuapp