diff --git a/R/class_junction.R b/R/class_junction.R
index d615604a..1d8f5f4f 100644
--- a/R/class_junction.R
+++ b/R/class_junction.R
@@ -3,32 +3,33 @@ junction_init <- function(
   splits = character(0),
   deps = list()
 ) {
-  splits <- make.unique(splits, sep = "_")
+  index <- seq_along(splits)
+  names(index) <- make.unique(splits, sep = "_")
   names(deps) <- names(deps) %|||% seq_along(deps)
   deps <- as_data_frame(deps)
-  junction_new(nexus, splits, deps)
+  junction_new(nexus, index, deps)
 }
 
-junction_new <- function(nexus = NULL, splits = NULL, deps = NULL) {
+junction_new <- function(nexus = NULL, index = NULL, deps = NULL) {
   out <- new.env(parent = emptyenv(), hash = FALSE)
   out$nexus <- nexus
-  out$splits <- splits
+  out$index <- index
   out$deps <- deps
   out
 }
 
 junction_upstream_edges <- function(junction) {
   from <- utils::stack(junction$deps)$values
-  to <- rep(junction$splits, times = ncol(junction$deps))
+  to <- rep(junction_splits(junction), times = ncol(junction$deps))
   data_frame(from = from, to = to)
 }
 
 junction_splits <- function(junction) {
-  as.character(junction$splits)
+  names(junction$index)
 }
 
 junction_transpose <- function(junction) {
-  splits <- junction$splits
+  splits <- junction_splits(junction)
   deps <- junction$deps
   out <- map_rows(deps, ~list(deps = unname(.x))) %||%
     replicate(length(splits), list(deps = character(0)), simplify = FALSE)
@@ -39,7 +40,7 @@ junction_transpose <- function(junction) {
 }
 
 junction_invalidate <- function(junction) {
-  junction$splits <- rep(NA_character_, length(junction$splits))
+  names(junction$index) <- rep(NA_character_, length(junction$index))
 }
 
 junction_validate_deps <- function(deps) {
@@ -52,6 +53,7 @@ junction_validate <- function(junction) {
   tar_assert_correct_fields(junction, junction_new)
   tar_assert_scalar(junction$nexus)
   tar_assert_chr(junction$nexus)
-  tar_assert_chr(junction$splits)
+  tar_assert_int(junction$index)
+  tar_assert_chr(junction_splits(junction))
   junction_validate_deps(junction$deps)
 }
diff --git a/tests/testthat/test-class_junction.R b/tests/testthat/test-class_junction.R
index b7d6699a..2ffbf40b 100644
--- a/tests/testthat/test-class_junction.R
+++ b/tests/testthat/test-class_junction.R
@@ -13,7 +13,7 @@ tar_test("junction_splits()", {
 tar_test("junction_invalidate()", {
   x <- junction_init("x", letters, list(a = LETTERS, b = rev(letters)))
   junction_invalidate(x)
-  expect_equal(junction_splits(x), rep(NA_character_, length(x$splits)))
+  expect_equal(junction_splits(x), rep(NA_character_, length(x$index)))
 })
 
 tar_test("junction_upstream_edges()", {
diff --git a/tests/testthat/test-class_stem.R b/tests/testthat/test-class_stem.R
index 5d2afbe8..9b3b0282 100644
--- a/tests/testthat/test-class_stem.R
+++ b/tests/testthat/test-class_stem.R
@@ -24,7 +24,7 @@ tar_test("stem$update_junction() on a good stem", {
   pipeline <- pipeline_init(list(x))
   stem_update_junction(x, pipeline)
   expect_silent(junction_validate(x$junction))
-  out <- x$junction$splits
+  out <- junction_splits(x$junction)
   expect_length(out, 10L)
   expect_true(all(grepl("abc_", out)))
 })