diff --git a/tools/internal_ci/linux/grpc_portability_build_only.cfg b/tools/internal_ci/linux/grpc_portability_build_only.cfg
index 8d76e5bc5d1..67c692ddd9b 100644
--- a/tools/internal_ci/linux/grpc_portability_build_only.cfg
+++ b/tools/internal_ci/linux/grpc_portability_build_only.cfg
@@ -26,5 +26,5 @@ action {
 
 env_vars {
   key: "RUN_TESTS_FLAGS"
-  value: "-f portability linux c++ --inner_jobs 8 -j 4 --internal_ci --build_only"
+  value: "-f portability linux c++ --inner_jobs 32 -j 1 --internal_ci --build_only"
 }