diff --git a/src/scheduler.rs b/src/scheduler.rs
index c1d548b2..3be76d43 100644
--- a/src/scheduler.rs
+++ b/src/scheduler.rs
@@ -776,12 +776,21 @@ impl<'a> Analyzer<'a> {
                     )?;
                     self.process_comprs(&comprs[..], scope, first_use, &mut used_vars)?;
                     let check_first_use = *op == AssignOp::ColEq;
-                    for var in self.gather_assigned_vars(lhs, scope, check_first_use, first_use)? {
+                    let assigned_vars =
+                        self.gather_assigned_vars(lhs, scope, check_first_use, first_use)?;
+
+                    for var in &assigned_vars {
                         definitions.push(Definition {
                             var,
                             used_vars: used_vars.clone(),
                         });
                     }
+                    if assigned_vars.is_empty() {
+                        definitions.push(Definition {
+                            var: "",
+                            used_vars: used_vars.clone(),
+                        });
+                    }
                 }
                 {
                     let (mut used_vars, comprs) = Self::gather_used_vars_comprs_index_vars(
@@ -792,12 +801,20 @@ impl<'a> Analyzer<'a> {
                     )?;
                     let check_first_use = false;
                     self.process_comprs(&comprs[..], scope, first_use, &mut used_vars)?;
-                    for var in self.gather_assigned_vars(rhs, scope, check_first_use, first_use)? {
+                    let assigned_vars =
+                        self.gather_assigned_vars(rhs, scope, check_first_use, first_use)?;
+                    for var in &assigned_vars {
                         definitions.push(Definition {
                             var,
                             used_vars: used_vars.clone(),
                         });
                     }
+                    if assigned_vars.is_empty() {
+                        definitions.push(Definition {
+                            var: "",
+                            used_vars: used_vars.clone(),
+                        });
+                    }
                 }
             }
         }
diff --git a/tests/opa/mod.rs b/tests/opa/mod.rs
index a89747fa..31cd7c5c 100644
--- a/tests/opa/mod.rs
+++ b/tests/opa/mod.rs
@@ -140,6 +140,8 @@ fn run_opa_tests() -> Result<()> {
                         }
                     }
 
+                    std::fs::write(path.join(format!("query{n}.text")), case.query.as_bytes())?;
+
                     println!("failed");
                     entry.1 += 1;
                     n += 1;