diff --git a/.github/workflows/test-query-engine.yml b/.github/workflows/test-query-engine.yml
index 8f1b5964db36..d66ab5a45f69 100644
--- a/.github/workflows/test-query-engine.yml
+++ b/.github/workflows/test-query-engine.yml
@@ -19,7 +19,7 @@ concurrency:
 
 jobs:
   rust-query-engine-tests:
-    name: "${{ matrix.database.name }} - ${{ matrix.engine_protocol }} ${{ matrix.partition }}"
+    name: "${{ matrix.database.name }} - ${{ matrix.engine_protocol }} ${{ matrix.relation_load_strategy }} ${{ matrix.partition }}"
 
     strategy:
       fail-fast: false
@@ -60,7 +60,16 @@ jobs:
             connector: "cockroachdb"
             version: "22.1"
         engine_protocol: [graphql, json]
+        relation_load_strategy: [join, query]
         partition: ["1/4", "2/4", "3/4", "4/4"]
+        exclude:
+          - relation_load_strategy: join
+            database:
+              [
+                { "connector": "mongodb" },
+                { "connector": "sqlite" },
+                { "connector": "mssql_2022" },
+              ]
 
     env:
       LOG_LEVEL: "info"
@@ -75,6 +84,7 @@ jobs:
       TEST_CONNECTOR: ${{ matrix.database.connector }}
       TEST_CONNECTOR_VERSION: ${{ matrix.database.version }}
       PRISMA_ENGINE_PROTOCOL: ${{ matrix.engine_protocol }}
+      PRISMA_RELATION_LOAD_STRATEGY: ${{ matrix.relation_load_strategy }}
 
     runs-on: ubuntu-latest
     steps:
diff --git a/query-engine/connector-test-kit-rs/query-engine-tests/tests/queries/simple/m2m.rs b/query-engine/connector-test-kit-rs/query-engine-tests/tests/queries/simple/m2m.rs
index 34c0e3078965..f8f860ebebfc 100644
--- a/query-engine/connector-test-kit-rs/query-engine-tests/tests/queries/simple/m2m.rs
+++ b/query-engine/connector-test-kit-rs/query-engine-tests/tests/queries/simple/m2m.rs
@@ -214,7 +214,7 @@ mod m2m {
         schema.to_owned()
     }
 
-    // https://github.com/prisma/prisma/issues/16390
+    // ! (https://github.com/prisma/prisma/issues/16390) - Skip on RLS::Query
     #[connector_test(schema(schema_16390), relation_mode = "prisma", only(Postgres))]
     async fn repro_16390(runner: Runner) -> TestResult<()> {
         run_query!(&runner, r#"mutation { createOneCategory(data: {}) { id } }"#);
@@ -225,12 +225,18 @@ mod m2m {
         run_query!(&runner, r#"mutation { deleteOneItem(where: { id: 1 }) { id } }"#);
 
         insta::assert_snapshot!(
-          run_query!(&runner, r#"{ findUniqueItem(where: { id: 1 }) { id categories { id } } }"#),
+          run_query!(&runner, r#"{
+                findUniqueItem(relationLoadStrategy: join, where: { id: 1 })
+                { id categories { id } } 
+            }"#),
           @r###"{"data":{"findUniqueItem":null}}"###
         );
 
         insta::assert_snapshot!(
-          run_query!(&runner, r#"{ findUniqueCategory(where: { id: 1 }) { id items { id } } }"#),
+          run_query!(&runner, r#"{
+                findUniqueCategory(relationLoadStrategy: join, where: { id: 1 })
+                { id items { id } }
+            }"#),
           @r###"{"data":{"findUniqueCategory":{"id":1,"items":[]}}}"###
         );
 
diff --git a/query-engine/core/src/query_graph_builder/read/utils.rs b/query-engine/core/src/query_graph_builder/read/utils.rs
index 745fdba608e3..9256175608be 100644
--- a/query-engine/core/src/query_graph_builder/read/utils.rs
+++ b/query-engine/core/src/query_graph_builder/read/utils.rs
@@ -1,5 +1,6 @@
 use super::*;
 use crate::{ArgumentListLookup, FieldPair, ParsedField, ReadQuery};
+use once_cell::sync::Lazy;
 use psl::datamodel_connector::{ConnectorCapability, JoinStrategySupport};
 use query_structure::{native_distinct_compatible_with_order_by, prelude::*, RelationLoadStrategy};
 use schema::{
@@ -259,6 +260,12 @@ pub(crate) fn get_relation_load_strategy(
     nested_queries: &[ReadQuery],
     query_schema: &QuerySchema,
 ) -> QueryGraphBuilderResult<RelationLoadStrategy> {
+    static DEFAULT_RELATION_LOAD_STRATEGY: Lazy<Option<RelationLoadStrategy>> = Lazy::new(|| {
+        std::env::var("PRISMA_RELATION_LOAD_STRATEGY")
+            .map(|e| e.as_str().try_into().unwrap())
+            .ok()
+    });
+
     match query_schema.join_strategy_support() {
         // Connector and database version supports the `Join` strategy...
         JoinStrategySupport::Yes => match requested_strategy {
@@ -269,8 +276,13 @@ pub(crate) fn get_relation_load_strategy(
             }
             // But requested strategy is `Query`.
             Some(RelationLoadStrategy::Query) => Ok(RelationLoadStrategy::Query),
-            // And requested strategy is `Join` or there's none selected, in which case the default is still `Join`.
-            Some(RelationLoadStrategy::Join) | None => Ok(RelationLoadStrategy::Join),
+            // Or requested strategy is `Join`.
+            Some(RelationLoadStrategy::Join) => Ok(RelationLoadStrategy::Join),
+            // or there's none selected, in which case we check for an envar else `Join`.
+            None => match *DEFAULT_RELATION_LOAD_STRATEGY {
+                Some(rls) => Ok(rls),
+                None => Ok(RelationLoadStrategy::Join),
+            },
         },
         // Connector supports `Join` strategy but database version does not...
         JoinStrategySupport::UnsupportedDbVersion => match requested_strategy {
diff --git a/query-engine/query-structure/src/query_arguments.rs b/query-engine/query-structure/src/query_arguments.rs
index eb895b46711d..39bc280564ff 100644
--- a/query-engine/query-structure/src/query_arguments.rs
+++ b/query-engine/query-structure/src/query_arguments.rs
@@ -40,6 +40,22 @@ impl RelationLoadStrategy {
     }
 }
 
+impl TryFrom<&str> for RelationLoadStrategy {
+    type Error = crate::error::DomainError;
+
+    fn try_from(value: &str) -> crate::Result<Self> {
+        // todo(team-orm#947) We ideally use the `load_strategy` enum defined in schema/constants, but first we need to extract the `schema-constants` crate.
+        match value {
+            "join" => Ok(RelationLoadStrategy::Join),
+            "query" => Ok(RelationLoadStrategy::Query),
+            _ => Err(DomainError::ConversionFailure(
+                value.to_owned(),
+                "RelationLoadStrategy".to_owned(),
+            )),
+        }
+    }
+}
+
 impl std::fmt::Debug for QueryArguments {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("QueryArguments")