diff --git a/components/eamxx/src/physics/p3/tests/CMakeLists.txt b/components/eamxx/src/physics/p3/tests/CMakeLists.txt
index 784d3436c884..129e3c455e26 100644
--- a/components/eamxx/src/physics/p3/tests/CMakeLists.txt
+++ b/components/eamxx/src/physics/p3/tests/CMakeLists.txt
@@ -59,7 +59,7 @@ endif()
 
 CreateUnitTest(p3_tests "${P3_TESTS_SRCS}"
   LIBS p3 p3_test_infra
-  EXE_ARGS "--flags=\\'${BASELINE_FILE_ARG}\\'"
+  EXE_ARGS "--args ${BASELINE_FILE_ARG}"
   THREADS 1 ${SCREAM_TEST_MAX_THREADS} ${SCREAM_TEST_THREAD_INC}
   LABELS "p3;physics")
 
@@ -68,7 +68,7 @@ CreateUnitTest(p3_tests "${P3_TESTS_SRCS}"
 if (SCREAM_ENABLE_BASELINE_TESTS)
   CreateUnitTest (p3_tests_fail p3_rain_sed_unit_tests.cpp
     LIBS p3 p3_test_infra
-    EXE_ARGS "--flags=\\'${BASELINE_FILE_ARG}\\'"
+    EXE_ARGS "--args ${BASELINE_FILE_ARG}"
     COMPILER_CXX_DEFS SCREAM_FORCE_RUN_DIFF
     LABELS "p3;physics;fail"
     ${FORCE_RUN_DIFF_FAILS})
@@ -77,7 +77,7 @@ endif()
 if (NOT SCREAM_P3_SMALL_KERNELS)
   CreateUnitTest(p3_sk_tests "${P3_TESTS_SRCS}"
     LIBS p3_sk p3_test_infra
-    EXE_ARGS "--flags=\\'${BASELINE_FILE_ARG}\\'"
+    EXE_ARGS "--args ${BASELINE_FILE_ARG}"
     THREADS 1 ${SCREAM_TEST_MAX_THREADS} ${SCREAM_TEST_THREAD_INC}
     LABELS "p3_sk;physics")
 
@@ -86,7 +86,7 @@ if (NOT SCREAM_P3_SMALL_KERNELS)
   if (SCREAM_ENABLE_BASELINE_TESTS)
     CreateUnitTest (p3_sk_tests_fail p3_rain_sed_unit_tests.cpp
       LIBS p3_sk p3_test_infra
-      EXE_ARGS "--flags=\\'${BASELINE_FILE_ARG}\\'"
+      EXE_ARGS "--args ${BASELINE_FILE_ARG}"
       COMPILER_CXX_DEFS SCREAM_FORCE_RUN_DIFF
       LABELS "p3_sk;physics;fail"
       ${FORCE_RUN_DIFF_FAILS})
diff --git a/components/eamxx/src/physics/p3/tests/infra/p3_unit_tests_common.hpp b/components/eamxx/src/physics/p3/tests/infra/p3_unit_tests_common.hpp
index 523315ae5ecc..9dd7dee95b31 100644
--- a/components/eamxx/src/physics/p3/tests/infra/p3_unit_tests_common.hpp
+++ b/components/eamxx/src/physics/p3/tests/infra/p3_unit_tests_common.hpp
@@ -85,28 +85,17 @@ struct UnitWrap {
       {
         Functions::p3_init(); // many tests will need fortran table data
         auto& ts = ekat::TestSession::get();
-        auto raw_flags = ts.flags.begin()->first;
-        std::stringstream ss(raw_flags);
-        std::string flag;
-        bool next_token_is_path = false;
-        while (ss >> flag) {
-          if (flag == "-c") {
-            m_baseline_action = COMPARE;
-          }
-          else if (flag == "-g") {
-            m_baseline_action = GENERATE;
-          }
-          else if (flag == "-n") {
-            m_baseline_action = NONE;
-          }
-          else if (flag == "-b") {
-            next_token_is_path = true;
-          }
-          else if (next_token_is_path) {
-            m_baseline_path = flag;
-            next_token_is_path = false;
-          }
+        if (ts.flags["c"]) {
+          m_baseline_action = COMPARE;
+        }
+        else if (ts.flags["g"]) {
+          m_baseline_action = GENERATE;
         }
+        else if (ts.flags["n"]) {
+          m_baseline_action = NONE;
+        }
+        m_baseline_path = ts.params["b"];
+
         EKAT_REQUIRE_MSG( !(m_baseline_action != NONE && m_baseline_path == ""),
                           "P3 unit test flags problem: baseline actions were requested but no baseline path was provided");