diff --git a/quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/integration/jaxrs/QuarkusKeycloakApplication.java b/quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/integration/jaxrs/QuarkusKeycloakApplication.java
index 848f7ace97..b3ca099659 100644
--- a/quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/integration/jaxrs/QuarkusKeycloakApplication.java
+++ b/quarkus/runtime/src/main/java/org/keycloak/quarkus/runtime/integration/jaxrs/QuarkusKeycloakApplication.java
@@ -25,7 +25,7 @@ import org.keycloak.quarkus.runtime.Environment;
 import org.keycloak.quarkus.runtime.cli.command.AbstractNonServerCommand;
 import org.keycloak.quarkus.runtime.configuration.Configuration;
 import org.keycloak.quarkus.runtime.configuration.MicroProfileConfigProvider;
-import org.keycloak.quarkus.runtime.configuration.mappers.PropertyMapper;
+import org.keycloak.quarkus.runtime.configuration.PropertyMappingInterceptor;
 import org.keycloak.quarkus.runtime.integration.QuarkusKeycloakSessionFactory;
 import org.keycloak.quarkus.runtime.integration.QuarkusPlatform;
 import org.keycloak.services.ServicesLogger;
@@ -95,13 +95,18 @@ public class QuarkusKeycloakApplication extends KeycloakApplication {
     }
 
     private String getOption(String option, String envVar) {
-        return Configuration.getOptionalKcValue(option).orElseGet(() -> {
-            String value = System.getenv(envVar);
-            if (value != null) {
-                ServicesLogger.LOGGER.usingDeprecatedEnvironmentVariable(envVar, Configuration.toEnvVarFormat(MicroProfileConfigProvider.NS_KEYCLOAK_PREFIX + option));
-            }
-            return value;
-        });
+        PropertyMappingInterceptor.disable(); // disable default handling
+        try {
+            return Configuration.getOptionalKcValue(option).orElseGet(() -> {
+                String value = System.getenv(envVar);
+                if (value != null) {
+                    ServicesLogger.LOGGER.usingDeprecatedEnvironmentVariable(envVar, Configuration.toEnvVarFormat(MicroProfileConfigProvider.NS_KEYCLOAK_PREFIX + option));
+                }
+                return value;
+            });
+        } finally {
+            PropertyMappingInterceptor.enable();
+        }
     }
 
     public boolean createTemporaryMasterRealmAdminUser(String adminUserName, String adminPassword, /*Integer adminExpiration,*/ KeycloakSession session) {
diff --git a/quarkus/tests/integration/src/test/java/org/keycloak/it/cli/dist/BuildAndStartDistTest.java b/quarkus/tests/integration/src/test/java/org/keycloak/it/cli/dist/BuildAndStartDistTest.java
index 831dc28a7c..552ae5d677 100644
--- a/quarkus/tests/integration/src/test/java/org/keycloak/it/cli/dist/BuildAndStartDistTest.java
+++ b/quarkus/tests/integration/src/test/java/org/keycloak/it/cli/dist/BuildAndStartDistTest.java
@@ -67,6 +67,13 @@ public class BuildAndStartDistTest {
         cliResult.assertBuild();
         cliResult.assertStarted();
     }
+    
+    @Test
+    @WithEnvVars({"KEYCLOAK_ADMIN", "oldadmin123", "KEYCLOAK_ADMIN_PASSWORD", "oldadmin123"})
+    @Launch({"start-dev"})
+    void testCreateLegacyAdmin(KeycloakDistribution dist, LaunchResult result) {
+        assertAdminCreation(dist, result, "oldadmin123", "oldadmin123", "oldadmin123");
+    }
 
     @Test
     @WithEnvVars({"KC_BOOTSTRAP_ADMIN_USERNAME", "admin123", "KC_BOOTSTRAP_ADMIN_PASSWORD", "admin123"})