diff --git a/cran-comments.md b/cran-comments.md
index 36f5d813f..e272e1695 100644
--- a/cran-comments.md
+++ b/cran-comments.md
@@ -1,9 +1,14 @@
 # CRAN notes for dodgr_0.2.5 submission
 
-I finally managed to reproduce the previous UBSCAN and valgrind errors observed
-by Brian Ripley on 20 Sept 2019. This submission definitely fixes, with both
-AddressSanitizer and valgrind on r-devel returning only the by-now usual loss of
-2-3000 bytes due to TBB code bundled in RcppParallel (see below). I humbly
+Email from Uwe Ligges (5 Oct 2019) suggests package check time exceeded 10
+minutes (13 min on r-devel-windows). I have correspondingly reduced numbers of
+tests run, observing a local reduction to < 50% of former test time.
+
+Other than that, and as stated on the immediately prior submission, I finally
+managed to reproduce the previous UBSCAN and valgrind errors observed by Brian
+Ripley on 20 Sept 2019. This submission definitely fixes, with both
+AddressSanitizer and valgrind on r-devel returning only the by-now usual loss
+of 2-3000 bytes due to TBB code bundled in RcppParallel (see below). I humbly
 apologise for any inconvenience which may have arisen during my previously
 unsuccessful attempts to resolve this issue.
 
diff --git a/tests/testthat/test-graph-fns.R b/tests/testthat/test-graph-fns.R
index 207fc8e37..bbff9e413 100644
--- a/tests/testthat/test-graph-fns.R
+++ b/tests/testthat/test-graph-fns.R
@@ -1,8 +1,12 @@
 context("dodgr graph functions")
 
+skip_on_cran ()
+
 test_all <- (identical (Sys.getenv ("MPADGE_LOCAL"), "true") |
              identical (Sys.getenv ("TRAVIS"), "true"))
 
+skip_if (!test_all)
+
 test_that("sample graph", {
     graph <- weight_streetnet (hampi)
     set.seed (1)
@@ -111,10 +115,7 @@ test_that("compare heaps", {
     #expect_true (ch$elapsed [igr] == max (ch$elapsed))
     # This actually fails on some machines (R oldrel on Windows) because elapsed
     # times are sometimes all very small *and equal*, so is turned off:
-    if (test_all)
-    {
-        #expect_true (ch$elapsed [igr] > min (ch$elapsed))
-    }
+    #expect_true (ch$elapsed [igr] > min (ch$elapsed))
 })
 
 test_that("dodgr2sf", {
diff --git a/tests/testthat/test-iso.R b/tests/testthat/test-iso.R
index 0d4a2b2fe..094aeb500 100644
--- a/tests/testthat/test-iso.R
+++ b/tests/testthat/test-iso.R
@@ -26,6 +26,9 @@ test_that("isodists", {
               expect_true (length (unique (d$dlim)) <= length (dlim))
 })
 
+skip_on_cran ()
+skip_if (!test_all)
+
 test_that ("turn penalty", {
               hsc <- sf_to_sc (hampi)
               net0 <- weight_streetnet (hsc, wt_profile = "bicycle")
diff --git a/tests/testthat/test-sc.R b/tests/testthat/test-sc.R
index a78bc12e8..ee0ff098d 100644
--- a/tests/testthat/test-sc.R
+++ b/tests/testthat/test-sc.R
@@ -3,6 +3,9 @@ context("SC")
 test_all <- (identical (Sys.getenv ("MPADGE_LOCAL"), "true") |
              identical (Sys.getenv ("TRAVIS"), "true"))
 
+skip_on_cran ()
+skip_if (!test_all)
+
 #library (osmdata)
 #devtools::load_all ("../../ropensci/osmdata", export_all = FALSE)
 #h2 <- opq ("hampi india") %>%