diff --git a/packages/cubejs-schema-compiler/src/adapter/BaseQuery.js b/packages/cubejs-schema-compiler/src/adapter/BaseQuery.js
index 5dd34176028ce..41b54704c90e5 100644
--- a/packages/cubejs-schema-compiler/src/adapter/BaseQuery.js
+++ b/packages/cubejs-schema-compiler/src/adapter/BaseQuery.js
@@ -3693,6 +3693,10 @@ export class BaseQuery {
     }
     // TODO: https://github.com/cube-js/cube.js/issues/4019
     // use single underscore for pre-aggregations to avoid fail of pre-aggregation name replace
+    const lowercaseName = name.toLowerCase();
+    if (lowercaseName === '__user' || lowercaseName === '__cubejoinfield') {
+      return name;
+    }
     return inflection.underscore(name).replace(/\./g, isPreAggregationName ? '_' : '__');
   }
 
diff --git a/rust/cubesql/cubesql/src/compile/engine/df/wrapper.rs b/rust/cubesql/cubesql/src/compile/engine/df/wrapper.rs
index 67d94e6547b52..da04e1a4cbc20 100644
--- a/rust/cubesql/cubesql/src/compile/engine/df/wrapper.rs
+++ b/rust/cubesql/cubesql/src/compile/engine/df/wrapper.rs
@@ -416,10 +416,7 @@ impl Remapper {
             LazyLock::new(|| Regex::new(r"[^a-zA-Z0-9_]").unwrap());
 
         let alias = start_from;
-        let mut truncated_alias = NON_ID_REGEX
-            .replace_all(&alias, "_")
-            .trim_start_matches("_")
-            .to_lowercase();
+        let mut truncated_alias = NON_ID_REGEX.replace_all(&alias, "_").to_lowercase();
         truncated_alias.truncate(16);
         let mut alias = truncated_alias.clone();
         for i in 1..10000 {
diff --git a/rust/cubesql/cubesql/src/compile/test/test_wrapper.rs b/rust/cubesql/cubesql/src/compile/test/test_wrapper.rs
index 6419939a1f90a..5db62bc5d772f 100644
--- a/rust/cubesql/cubesql/src/compile/test/test_wrapper.rs
+++ b/rust/cubesql/cubesql/src/compile/test/test_wrapper.rs
@@ -925,9 +925,9 @@ async fn test_case_wrapper_with_system_fields() {
             .wrapped_sql
             .sql
             .contains(
-                "\\\"cubeName\\\":\\\"KibanaSampleDataEcommerce\\\",\\\"alias\\\":\\\"user\\\""
+                "\\\"cubeName\\\":\\\"KibanaSampleDataEcommerce\\\",\\\"alias\\\":\\\"__user\\\""
             ),
-        r#"SQL contains `\"cubeName\":\"KibanaSampleDataEcommerce\",\"alias\":\"user\"` {}"#,
+        r#"SQL contains `\"cubeName\":\"KibanaSampleDataEcommerce\",\"alias\":\"__user\"` {}"#,
         logical_plan.find_cube_scan_wrapped_sql().wrapped_sql.sql
     );