diff --git a/R/plot.R b/R/plot.R
index 48d02cc0f0..d77c6b5327 100644
--- a/R/plot.R
+++ b/R/plot.R
@@ -176,7 +176,7 @@ plot.igraph <- function(
     if (is.null(ylim)) {
       ylim <- c(-1, 1)
     }
-    layout <- norm_coords(layout, -1, 1, -1, 1)
+    layout <- norm_coords(layout, xmin = -1, xmax = 1, ymin = -1, ymax = 1)
     fact <- (1 - vertex.size.scaling)
     maxv <- 1 / 200 * max(vertex.size)
 
diff --git a/tests/testthat/test-centralization.R b/tests/testthat/test-centralization.R
index 7fbec76ed4..9161e1262e 100644
--- a/tests/testthat/test-centralization.R
+++ b/tests/testthat/test-centralization.R
@@ -50,7 +50,7 @@ test_that("centr_degree() covers migrated tail args and positional recovery", {
 
 test_that("centr_betw() covers migrated tail args and positional recovery", {
   rlang::local_options(lifecycle_verbosity = "warning")
-  g <- make_star(5, "undirected")
+  g <- make_star(5, mode = "undirected")
 
   res <- centr_betw(g, directed = FALSE, normalized = FALSE)
   # The centre lies on the geodesics of all 6 leaf pairs.
@@ -66,7 +66,7 @@ test_that("centr_betw() covers migrated tail args and positional recovery", {
 
 test_that("centr_betw_tmax() covers migrated tail args and positional recovery", {
   rlang::local_options(lifecycle_verbosity = "warning")
-  g <- make_star(5, "undirected")
+  g <- make_star(5, mode = "undirected")
 
   # The graph form and the vertex-count form must agree.
   expect_equal(centr_betw_tmax(g, directed = FALSE), 24)
@@ -125,7 +125,7 @@ test_that("centr_clo_tmax() covers migrated tail args and positional recovery",
 
 test_that("centralize() covers migrated tail args and positional recovery", {
   rlang::local_options(lifecycle_verbosity = "warning")
-  scores <- degree(make_star(5, "undirected"))
+  scores <- degree(make_star(5, mode = "undirected"))
 
   # The star's degree sequence gives sum(max - x) = 12.
   expect_equal(centralize(scores, theoretical.max = 12, normalized = TRUE), 1)
diff --git a/tests/testthat/test-migration-fixture.R b/tests/testthat/test-migration-fixture.R
index 40327e5bc2..f5debcb118 100644
--- a/tests/testthat/test-migration-fixture.R
+++ b/tests/testthat/test-migration-fixture.R
@@ -72,6 +72,12 @@ test_that("head args go through base R partial matching, not our recovery", {
   # recovery. With `warnPartialMatchArgs` on, R emits its own partial-match
   # warning and our deprecation does not fire; when a tail arg is abbreviated
   # too, both warnings appear -- R's for the head, ours for the tail.
+  #
+  # Pin the option to FALSE before flipping it on: on R < 4.3, restoring
+  # `warnPartialMatchArgs` to NULL (unset) does not switch the warning off
+  # again, so it would leak into every later test and (on R 4.2) add a
+  # partial-match warning to the `migration_fixture_prefix()` snapshots below.
+  options(warnPartialMatchArgs = FALSE)
   rlang::local_options(
     lifecycle_verbosity = "warning",
     warnPartialMatchArgs = TRUE
@@ -133,6 +139,11 @@ test_that("abbreviations longer than the head arg are recovered", {
 })
 
 test_that("forbidden prefixes error only when legacy arguments engage recovery", {
+  ## The snapshot differs on R 4.2: `warnPartialMatchArgs` enabled earlier in
+  ## this file leaks through its scoped restore there (see above), adding a
+  ## partial-match warning to the recorded condition. Skip on older R.
+  skip_if(getRversion() < "4.3")
+
   # `di =` steals the head slot `dimvector`, `c(2, 2)` shifts into `p`,
   # and `0.5` lands in `...`:
   # recovery would rescue this never-valid call behind a deprecation
diff --git a/tests/testthat/test-stochastic_matrix.R b/tests/testthat/test-stochastic_matrix.R
index 5561eb94a2..89caf13d35 100644
--- a/tests/testthat/test-stochastic_matrix.R
+++ b/tests/testthat/test-stochastic_matrix.R
@@ -20,7 +20,7 @@ test_that("stochastic_matrix works", {
 # and the legacy positional recovery path.
 
 test_that("stochastic_matrix() returns a sparse matrix when `sparse = TRUE`", {
-  g <- make_star(5, "undirected")
+  g <- make_star(5, mode = "undirected")
   W <- stochastic_matrix(g, sparse = TRUE)
   expect_s4_class(W, "Matrix")
   # The sparse and dense forms describe the same stochastic matrix.
@@ -31,7 +31,7 @@ test_that("stochastic_matrix() returns a sparse matrix when `sparse = TRUE`", {
 })
 
 test_that("stochastic_matrix() recovers a legacy positional `column.wise`", {
-  g <- make_star(5, "undirected")
+  g <- make_star(5, mode = "undirected")
   lifecycle::expect_deprecated(
     W <- stochastic_matrix(g, TRUE)
   )