diff -up ./lib/certhigh/certvfypkix.c.revert_libpkix ./lib/certhigh/certvfypkix.c
--- ./lib/certhigh/certvfypkix.c.revert_libpkix	2024-06-07 09:26:03.000000000 -0700
+++ ./lib/certhigh/certvfypkix.c	2024-07-05 13:18:34.285174699 -0700
@@ -39,7 +39,7 @@ pkix_pl_lifecycle_ObjectTableUpdate(int
 PRInt32 parallelFnInvocationCount;
 #endif /* PKIX_OBJECT_LEAK_TEST */
 
-static PRBool usePKIXValidationEngine = PR_TRUE;
+static PRBool usePKIXValidationEngine = PR_FALSE;
 #endif /* NSS_DISABLE_LIBPKIX */
 
 /*
diff -up ./lib/nss/nssinit.c.revert_libpkix ./lib/nss/nssinit.c
--- ./lib/nss/nssinit.c.revert_libpkix	2024-06-07 09:26:03.000000000 -0700
+++ ./lib/nss/nssinit.c	2024-07-05 13:18:34.285174699 -0700
@@ -764,9 +764,9 @@ nss_Init(const char *configdir, const ch
         if (pkixError != NULL) {
             goto loser;
         } else {
-            char *ev = PR_GetEnvSecure("NSS_DISABLE_PKIX_VERIFY");
+            char *ev = PR_GetEnvSecure("NSS_ENABLE_PKIX_VERIFY");
             if (ev && ev[0]) {
-                CERT_SetUsePKIXForValidation(PR_FALSE);
+                CERT_SetUsePKIXForValidation(PR_TRUE);
             }
         }
 #endif /* NSS_DISABLE_LIBPKIX */
diff -up ./tests/all.sh.revert_libpkix ./tests/all.sh
--- ./tests/all.sh.revert_libpkix	2024-06-07 09:26:03.000000000 -0700
+++ ./tests/all.sh	2024-07-05 13:18:34.285174699 -0700
@@ -143,9 +143,6 @@ run_cycle_standard()
 {
     TEST_MODE=STANDARD
 
-    NSS_DISABLE_LIBPKIX_VERIFY="1"
-    export NSS_DISABLE_LIBPKIX_VERIFY
-
     TESTS="${ALL_TESTS}"
     TESTS_SKIP="libpkix pkits"
 
@@ -153,8 +150,6 @@ run_cycle_standard()
     export NSS_DEFAULT_DB_TYPE
 
     run_tests
-
-    unset NSS_DISABLE_LIBPKIX_VERIFY
 }
 
 ############################ run_cycle_pkix ############################
@@ -172,6 +167,9 @@ run_cycle_pkix()
     mkdir -p "${HOSTDIR}"
     init_directories
 
+    NSS_ENABLE_PKIX_VERIFY="1"
+    export NSS_ENABLE_PKIX_VERIFY
+
     TESTS="${ALL_TESTS}"
     TESTS_SKIP="cipher dbtests sdr crmf smime merge multinit"
 
diff -up ./tests/common/init.sh.revert_libpkix ./tests/common/init.sh
--- ./tests/common/init.sh.revert_libpkix	2024-06-07 09:26:03.000000000 -0700
+++ ./tests/common/init.sh	2024-07-05 13:18:34.285174699 -0700
@@ -140,8 +140,8 @@ if [ -z "${INIT_SOURCED}" -o "${INIT_SOU
         echo "NSS_SSL_RUN=\"${NSS_SSL_RUN}\""
         echo "NSS_DEFAULT_DB_TYPE=${NSS_DEFAULT_DB_TYPE}"
         echo "export NSS_DEFAULT_DB_TYPE"
-        echo "NSS_DISABLE_PKIX_VERIFY=${NSS_DISABLE_PKIX_VERIFY}"
-        echo "export NSS_DISABLE_PKIX_VERIFY"
+        echo "NSS_ENABLE_PKIX_VERIFY=${NSS_ENABLE_PKIX_VERIFY}"
+        echo "export NSS_ENABLE_PKIX_VERIFY"
         echo "init_directories"
     }
 
diff -up ./tests/ssl/ssl.sh.revert_libpkix ./tests/ssl/ssl.sh
--- ./tests/ssl/ssl.sh.revert_libpkix	2024-07-05 13:18:34.267174492 -0700
+++ ./tests/ssl/ssl.sh	2024-07-05 13:23:15.295402481 -0700
@@ -971,8 +971,9 @@ ssl_policy_pkix_ocsp()
       return 0
   fi
 
-  PKIX_SAVE=${NSS_DISABLE_LIBPKIX_VERIFY-"unset"}
-  unset NSS_DISABLE_LIBPKIX_VERIFY
+  PKIX_SAVE=${NSS_ENABLE_PKIX_VERIFY-"unset"}
+  NSS_ENABLE_PKIX_VERIFY="1"
+  export NSS_ENABLE_PKIX_VERIFY
 
   testname=""
 
@@ -997,10 +998,12 @@ ssl_policy_pkix_ocsp()
   html_msg $RET $RET_EXP "${testname}" \
            "produced a returncode of $RET, expected is $RET_EXP"
 
-  if [ "{PKIX_SAVE}" != "unset" ]; then
-      export NSS_DISABLE_LIBPKIX_VERIFY=${PKIX_SAVE}
+  if [ "${PKIX_SAVE}" = "unset" ]; then
+      unset NSS_ENABLE_PKIX_VERIFY
+  else
+      NSS_ENABLE_PKIX_VERIFY=${PKIX_SAVE}
+      export NSS_ENABLE_PKIX_VERIFY
   fi
-
   cp ${P_R_SERVERDIR}/pkcs11.txt.sav ${P_R_SERVERDIR}/pkcs11.txt
 
   html "</TABLE><BR>"