diff --git a/src/python/pants/engine/native.py b/src/python/pants/engine/native.py
index 926a73a74f0..7b1bfc803fc 100644
--- a/src/python/pants/engine/native.py
+++ b/src/python/pants/engine/native.py
@@ -109,7 +109,7 @@
 typedef Buffer              (*extern_ptr_val_to_str)(ExternContext*, Value*);
 typedef _Bool               (*extern_ptr_satisfied_by)(ExternContext*, Value*, Value*);
 typedef _Bool               (*extern_ptr_satisfied_by_type)(ExternContext*, Value*, TypeId*);
-typedef Value               (*extern_ptr_store_list)(ExternContext*, Value**, uint64_t, _Bool);
+typedef Value               (*extern_ptr_store_tuple)(ExternContext*, Value*, uint64_t);
 typedef Value               (*extern_ptr_store_bytes)(ExternContext*, uint8_t*, uint64_t);
 typedef Value               (*extern_ptr_store_i32)(ExternContext*, int32_t);
 typedef ValueBuffer         (*extern_ptr_project_multi)(ExternContext*, Value*, uint8_t*, uint64_t);
@@ -153,7 +153,7 @@
                  extern_ptr_val_to_str,
                  extern_ptr_satisfied_by,
                  extern_ptr_satisfied_by_type,
-                 extern_ptr_store_list,
+                 extern_ptr_store_tuple,
                  extern_ptr_store_bytes,
                  extern_ptr_store_i32,
                  extern_ptr_project_ignoring_type,
@@ -244,7 +244,7 @@
   Buffer              extern_val_to_str(ExternContext*, Value*);
   _Bool               extern_satisfied_by(ExternContext*, Value*, Value*);
   _Bool               extern_satisfied_by_type(ExternContext*, Value*, TypeId*);
-  Value               extern_store_list(ExternContext*, Value**, uint64_t, _Bool);
+  Value               extern_store_tuple(ExternContext*, Value*, uint64_t);
   Value               extern_store_bytes(ExternContext*, uint8_t*, uint64_t);
   Value               extern_store_i32(ExternContext*, int32_t);
   Value               extern_project_ignoring_type(ExternContext*, Value*, uint8_t*, uint64_t);
@@ -396,22 +396,10 @@ def extern_satisfied_by_type(context_handle, constraint_val, cls_id):
     return constraint.satisfied_by_type(c.from_id(cls_id.id_))
 
   @ffi.def_extern()
-  def extern_store_list(context_handle, vals_ptr_ptr, vals_len, merge):
+  def extern_store_tuple(context_handle, vals_ptr, vals_len):
     """Given storage and an array of Values, return a new Value to represent the list."""
     c = ffi.from_handle(context_handle)
-    vals = tuple(c.from_value(val) for val in ffi.unpack(vals_ptr_ptr, vals_len))
-    if merge:
-      # Expect each obj to represent a list, and do a de-duping merge.
-      merged_set = set()
-      def merged():
-        for outer_val in vals:
-          for inner_val in outer_val:
-            if inner_val in merged_set:
-              continue
-            merged_set.add(inner_val)
-            yield inner_val
-      vals = tuple(merged())
-    return c.to_value(vals)
+    return c.to_value(tuple(c.from_value(val) for val in ffi.unpack(vals_ptr, vals_len)))
 
   @ffi.def_extern()
   def extern_store_bytes(context_handle, bytes_ptr, bytes_len):
@@ -674,7 +662,7 @@ def init_externs():
                            self.ffi_lib.extern_val_to_str,
                            self.ffi_lib.extern_satisfied_by,
                            self.ffi_lib.extern_satisfied_by_type,
-                           self.ffi_lib.extern_store_list,
+                           self.ffi_lib.extern_store_tuple,
                            self.ffi_lib.extern_store_bytes,
                            self.ffi_lib.extern_store_i32,
                            self.ffi_lib.extern_project_ignoring_type,
diff --git a/src/rust/engine/src/externs.rs b/src/rust/engine/src/externs.rs
index 01dd308c677..5c44bafa3a2 100644
--- a/src/rust/engine/src/externs.rs
+++ b/src/rust/engine/src/externs.rs
@@ -54,16 +54,8 @@ pub fn satisfied_by_type(constraint: &TypeConstraint, cls: &TypeId) -> bool {
   with_externs(|e| (e.satisfied_by_type)(e.context, interns.get(&constraint.0), cls))
 }
 
-pub fn store_list(values: Vec<&Value>, merge: bool) -> Value {
-  with_externs(|e| {
-    let values_clone: Vec<*const Value> = values.into_iter().map(|v| v as *const Value).collect();
-    (e.store_list)(
-      e.context,
-      values_clone.as_ptr(),
-      values_clone.len() as u64,
-      merge,
-    )
-  })
+pub fn store_tuple(values: &[Value]) -> Value {
+  with_externs(|e| (e.store_tuple)(e.context, values.as_ptr(), values.len() as u64))
 }
 
 pub fn store_bytes(bytes: &[u8]) -> Value {
@@ -227,7 +219,7 @@ pub struct Externs {
   pub drop_handles: DropHandlesExtern,
   pub satisfied_by: SatisfiedByExtern,
   pub satisfied_by_type: SatisfiedByTypeExtern,
-  pub store_list: StoreListExtern,
+  pub store_tuple: StoreTupleExtern,
   pub store_bytes: StoreBytesExtern,
   pub store_i32: StoreI32Extern,
   pub project_ignoring_type: ProjectIgnoringTypeExtern,
@@ -245,10 +237,8 @@ unsafe impl Send for Externs {}
 
 pub type LogExtern = extern "C" fn(*const ExternContext, u8, str_ptr: *const u8, str_len: u64);
 
-// TODO: Type alias used to avoid rustfmt breaking itself by rendering a 101 character line.
-pub type SatisfedBool = bool;
 pub type SatisfiedByExtern =
-  extern "C" fn(*const ExternContext, *const Value, *const Value) -> SatisfedBool;
+  extern "C" fn(*const ExternContext, *const Value, *const Value) -> bool;
 
 pub type SatisfiedByTypeExtern =
   extern "C" fn(*const ExternContext, *const Value, *const TypeId) -> bool;
@@ -261,8 +251,7 @@ pub type CloneValExtern = extern "C" fn(*const ExternContext, *const Value) -> V
 
 pub type DropHandlesExtern = extern "C" fn(*const ExternContext, *const Handle, u64);
 
-pub type StoreListExtern =
-  extern "C" fn(*const ExternContext, *const *const Value, u64, bool) -> Value;
+pub type StoreTupleExtern = extern "C" fn(*const ExternContext, *const Value, u64) -> Value;
 
 pub type StoreBytesExtern = extern "C" fn(*const ExternContext, *const u8, u64) -> Value;
 
diff --git a/src/rust/engine/src/lib.rs b/src/rust/engine/src/lib.rs
index 0097a83f2d3..045a3d542b3 100644
--- a/src/rust/engine/src/lib.rs
+++ b/src/rust/engine/src/lib.rs
@@ -45,7 +45,7 @@ use externs::{Buffer, BufferBuffer, CallExtern, CloneValExtern, CreateExceptionE
               DropHandlesExtern, EqualsExtern, EvalExtern, ExternContext, Externs,
               GeneratorSendExtern, IdentifyExtern, LogExtern, ProjectIgnoringTypeExtern,
               ProjectMultiExtern, PyResult, SatisfiedByExtern, SatisfiedByTypeExtern,
-              StoreBytesExtern, StoreI32Extern, StoreListExtern, TypeIdBuffer, TypeToStrExtern,
+              StoreBytesExtern, StoreI32Extern, StoreTupleExtern, TypeIdBuffer, TypeToStrExtern,
               ValToStrExtern};
 use rule_graph::{GraphMaker, RuleGraph};
 use scheduler::{ExecutionRequest, RootResult, Scheduler};
@@ -134,7 +134,7 @@ pub extern "C" fn externs_set(
   val_to_str: ValToStrExtern,
   satisfied_by: SatisfiedByExtern,
   satisfied_by_type: SatisfiedByTypeExtern,
-  store_list: StoreListExtern,
+  store_tuple: StoreTupleExtern,
   store_bytes: StoreBytesExtern,
   store_i32: StoreI32Extern,
   project_ignoring_type: ProjectIgnoringTypeExtern,
@@ -157,7 +157,7 @@ pub extern "C" fn externs_set(
     val_to_str,
     satisfied_by,
     satisfied_by_type,
-    store_list,
+    store_tuple,
     store_bytes,
     store_i32,
     project_ignoring_type,
@@ -456,7 +456,7 @@ pub extern "C" fn execution_request_destroy(ptr: *mut ExecutionRequest) {
 pub extern "C" fn validator_run(scheduler_ptr: *mut Scheduler) -> Value {
   with_scheduler(scheduler_ptr, |scheduler| {
     match scheduler.core.rule_graph.validate() {
-      Result::Ok(_) => externs::store_list(vec![], false),
+      Result::Ok(_) => externs::store_tuple(&[]),
       Result::Err(msg) => externs::create_exception(&msg),
     }
   })
diff --git a/src/rust/engine/src/nodes.rs b/src/rust/engine/src/nodes.rs
index 5591ab1d3c4..71e1c9a6881 100644
--- a/src/rust/engine/src/nodes.rs
+++ b/src/rust/engine/src/nodes.rs
@@ -492,7 +492,7 @@ impl SelectDependencies {
               .then(move |dep_values_res| {
                 // Finally, store the resulting values.
                 match dep_values_res {
-                  Ok(dep_values) => Ok(externs::store_list(dep_values.iter().collect(), false)),
+                  Ok(dep_values) => Ok(externs::store_tuple(&dep_values)),
                   Err(failure) => Err(was_required(failure)),
                 }
               })
@@ -736,7 +736,7 @@ impl Snapshot {
       &[
         externs::store_bytes(&(item.digest.0).to_hex().as_bytes()),
         externs::store_i32(item.digest.1 as i32),
-        externs::store_list(path_stats.iter().collect(), false),
+        externs::store_tuple(&path_stats),
       ],
     )
   }
@@ -784,7 +784,7 @@ impl Snapshot {
       .collect();
     externs::unsafe_call(
       &context.core.types.construct_files_content,
-      &[externs::store_list(entries.iter().collect(), false)],
+      &[externs::store_tuple(&entries)],
     )
   }
 }
@@ -894,7 +894,7 @@ impl Task {
             .map(|vs| future::Loop::Continue(vs.into_iter().next().unwrap()))
             .to_boxed(),
           externs::GeneratorResponse::GetMulti(gets) => Self::gen_get(&context, entry, gets)
-            .map(|vs| future::Loop::Continue(externs::store_list(vs.iter().collect(), false)))
+            .map(|vs| future::Loop::Continue(externs::store_tuple(&vs)))
             .to_boxed(),
           externs::GeneratorResponse::Break(val) => future::ok(future::Loop::Break(val)).to_boxed(),
         }