diff --git a/scala/private/phases/phase_scalafmt.bzl b/scala/private/phases/phase_scalafmt.bzl
index a42410980e..0f8f19728f 100644
--- a/scala/private/phases/phase_scalafmt.bzl
+++ b/scala/private/phases/phase_scalafmt.bzl
@@ -10,19 +10,23 @@ load(
 
 def phase_scalafmt(ctx, p):
     if ctx.attr.format:
-        manifest, files = _build_format(ctx)
+        manifest, files, srcs = _build_format(ctx)
         _formatter(ctx, manifest, files, ctx.file._runner, ctx.outputs.scalafmt_runner)
         _formatter(ctx, manifest, files, ctx.file._testrunner, ctx.outputs.scalafmt_testrunner)
+        # Return a depset containing all the relevant files, so a wrapping `sh_test` can successfully access them.
+        return struct(runfiles = depset([manifest] + files + srcs))
     else:
         _write_empty_content(ctx, ctx.outputs.scalafmt_runner)
         _write_empty_content(ctx, ctx.outputs.scalafmt_testrunner)
 
 def _build_format(ctx):
     files = []
+    srcs = []
     manifest_content = []
     for src in ctx.files.srcs:
         # only format scala source files, not generated files
         if src.path.endswith(_scala_extension) and src.is_source:
+            srcs.append(src)
             file = ctx.actions.declare_file("{}.fmt.output".format(src.short_path))
             files.append(file)
             ctx.actions.run(
@@ -40,7 +44,7 @@ def _build_format(ctx):
     manifest = ctx.actions.declare_file("format/{}/manifest.txt".format(ctx.label.name))
     ctx.actions.write(manifest, "\n".join(manifest_content) + "\n")
 
-    return manifest, files
+    return manifest, files, srcs
 
 def _formatter(ctx, manifest, files, template, output_runner):
     ctx.actions.run_shell(
diff --git a/scala/scalafmt/private/format-test.template.sh b/scala/scalafmt/private/format-test.template.sh
index 0ca9d99b90..0648ff52d7 100644
--- a/scala/scalafmt/private/format-test.template.sh
+++ b/scala/scalafmt/private/format-test.template.sh
@@ -1,15 +1,24 @@
 #!/bin/bash -e
-WORKSPACE_ROOT="${1:-$BUILD_WORKSPACE_DIRECTORY}"
+
+# Explanation: IF $BUILD_WORKSPACE_DIRECTORY is set to something (as it would be during a
+# `bazel run`), then append a trailing `/`.  If it's not set (as it wouldn't be during
+# a `bazel test` invocation in a wrapping `sh_test` rule), then elide the trailing `/`, and
+# instead rely upon a relative path from the test's runtrees.  The corresponding change
+# to `phase_scalafmt` places the source files into the `runfiles` set, so they'll be symlinked
+# correctly in the appropriate relative location.
+WORKSPACE_ROOT="${1:-${BUILD_WORKSPACE_DIRECTORY}${BUILD_WORKSPACE_DIRECTORY:+/}}"
+
 RUNPATH="${TEST_SRCDIR-$0.runfiles}"/%workspace%
 RUNPATH=(${RUNPATH//bin/ })
 RUNPATH="${RUNPATH[0]}"bin
 
 EXIT=0
+
 while read original formatted; do
     if [[ ! -z "$original" ]] && [[ ! -z "$formatted" ]]; then
-        if ! cmp -s "$WORKSPACE_ROOT/$original" "$RUNPATH/$formatted"; then
+        if ! cmp -s "${WORKSPACE_ROOT}$original" "$RUNPATH/$formatted"; then
             echo $original
-            diff "$WORKSPACE_ROOT/$original" "$RUNPATH/$formatted" || true
+            diff "${WORKSPACE_ROOT}$original" "$RUNPATH/$formatted" || true
             EXIT=1
         fi
     fi