diff --git a/DESCRIPTION b/DESCRIPTION
index 31269c1..e58ad19 100755
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: githist
 Title: Code analyses traced along the 'git' history of a package
-Version: 0.1.0.037
+Version: 0.1.0.038
 Authors@R: 
     person("Mark", "Padgham", , "mark.padgham@email.com", role = c("aut", "cre"),
            comment = c(ORCID = "0000-0003-2172-5265"))
diff --git a/codemeta.json b/codemeta.json
index 42d2cdb..bd40416 100644
--- a/codemeta.json
+++ b/codemeta.json
@@ -8,7 +8,7 @@
   "codeRepository": "https://github.com/ropensci-review-tools/githist",
   "issueTracker": "https://github.com/ropensci-review-tools/githist/issues",
   "license": "https://spdx.org/licenses/GPL-3.0",
-  "version": "0.1.0.037",
+  "version": "0.1.0.038",
   "programmingLanguage": {
     "@type": "ComputerLanguage",
     "name": "R",
diff --git a/tests/testthat/test-testpkg.R b/tests/testthat/test-testpkg.R
index 21a2cbf..47cc89c 100644
--- a/tests/testthat/test-testpkg.R
+++ b/tests/testthat/test-testpkg.R
@@ -9,7 +9,7 @@ test_that ("testpkg and input errors", {
     expect_error (githist (path, step_size = 1:2, num_cores = 1L))
     expect_error (githist (path, step_size = "1", num_cores = 1L))
 
-    res <- githist (path, num_cores = 1L)
+    res <- githist (path, num_cores = 1L, step_days = 0L)
     fs::dir_delete (path)
 
     expect_type (res, "list")
@@ -23,27 +23,28 @@ test_that ("githist parameters", {
     flist <- unzip (pkg, exdir = fs::path_temp ())
     path <- fs::path_dir (flist [1])
 
-    res0 <- githist (path, num_cores = 1L)
-    n0 <- vapply (res0, nrow, integer (1L))
+    res0 <- githist (path, step_days = 0L, num_cores = 1L)
     fs::dir_delete (path)
 
     flist <- unzip (pkg, exdir = fs::path_temp ())
-    res1 <- githist (path, n = 2L, num_cores = 1L)
-    n1 <- vapply (res1, nrow, integer (1L))
+    res1 <- githist (path, n = 2L, step_days = 0L, num_cores = 1L)
     fs::dir_delete (path)
 
+    n0 <- vapply (res0, nrow, integer (1L))
+    n1 <- vapply (res1, nrow, integer (1L))
+    expect_true (all (n0 > n1))
+    # `n = 2L` selects dates [1:2] from original data:
+    expect_identical (res0$desc_data$date [1:2], res1$desc_data$date)
+
     flist <- unzip (pkg, exdir = fs::path_temp ())
-    res2 <- githist (path, n = 2L, step_size = 2L, num_cores = 1L)
-    n2 <- vapply (res2, nrow, integer (1L))
+    res2 <- githist (path, n = 2L, step_days = 1L, num_cores = 1L)
     fs::dir_delete (path)
 
-    expect_true (all (n0 > n1))
+    n2 <- vapply (res2, nrow, integer (1L))
     expect_true (all (n0 > n2))
-    expect_true (nrow (res0$desc_data) > 2L)
-    expect_equal (nrow (res1$desc_data), 2L)
-    expect_equal (nrow (res2$desc_data), 2L)
-
-    d1 <- abs (diff (res1$desc_data$date, units = "s"))
-    d2 <- abs (diff (res2$desc_data$date, units = "s"))
-    expect_true (mean (d1) < mean (d2))
+    expect_true (all (n1 > n2))
+    expect_equal (
+        length (res2$desc_dat$date),
+        length (unique (res2$desc_data$date))
+    )
 })