diff --git a/tests/testthat/test-bibtex_reader.R b/tests/testthat/test-bibtex_reader.R
index 3724b41..77500d5 100644
--- a/tests/testthat/test-bibtex_reader.R
+++ b/tests/testthat/test-bibtex_reader.R
@@ -1,6 +1,8 @@
 context("bibtex_reader")
 
 test_that("bibtex_reader: works", {
+  skip_on_cran()
+  
   z <- system.file('extdata/crossref.bib', package = "handlr")
   x <- bibtex_reader(z)
 
diff --git a/tests/testthat/test-bibtex_writer.R b/tests/testthat/test-bibtex_writer.R
index 62342f1..7363d9e 100644
--- a/tests/testthat/test-bibtex_writer.R
+++ b/tests/testthat/test-bibtex_writer.R
@@ -1,6 +1,8 @@
 context("bibtex_writer")
 
 test_that("bibtex_writer: works", {
+  skip_on_cran()
+
   z <- system.file('extdata/citeproc.json', package = "handlr")
   tmp <- citeproc_reader(z)
   x <- bibtex_writer(z = tmp)
@@ -10,6 +12,8 @@ test_that("bibtex_writer: works", {
 })
 
 test_that("bibtex_writer: write from citeproc json", {
+  skip_on_cran()
+
   z <- system.file('extdata/citeproc.json', package = "handlr")
   tmp <- citeproc_reader(z)
   x <- bibtex_writer(z = tmp)
@@ -17,6 +21,8 @@ test_that("bibtex_writer: write from citeproc json", {
 })
 
 test_that("bibtex_writer: output gives back same as input from bibtex_reader", {
+  skip_on_cran()
+  
   z <- system.file('extdata/bibtex2.bib', package = "handlr")
   w <- bibtex_reader(z)
   bw_out <- bibtex_writer(w)
diff --git a/tests/testthat/test-citeproc_reader.R b/tests/testthat/test-citeproc_reader.R
index 4feccc2..54164f6 100644
--- a/tests/testthat/test-citeproc_reader.R
+++ b/tests/testthat/test-citeproc_reader.R
@@ -1,6 +1,8 @@
 context("citeproc_reader")
 
 test_that("citeproc_reader: works", {
+  skip_on_cran()
+  
   z <- system.file('extdata/citeproc.json', package = "handlr")
   x <- citeproc_reader(z)
 
diff --git a/tests/testthat/test-client.R b/tests/testthat/test-client.R
index 8a2cc64..786b06a 100644
--- a/tests/testthat/test-client.R
+++ b/tests/testthat/test-client.R
@@ -1,5 +1,7 @@
 context("HandlrClient")
 
+skip_on_cran()
+
 test_that("HandlrClient class: after initializing, but before reading", {
   expect_is(HandlrClient, "R6ClassGenerator")
   expect_is(HandlrClient$new, "function")
diff --git a/tests/testthat/test-client_guesses_format.R b/tests/testthat/test-client_guesses_format.R
index 259f394..d7ce765 100644
--- a/tests/testthat/test-client_guesses_format.R
+++ b/tests/testthat/test-client_guesses_format.R
@@ -1,5 +1,7 @@
 context("HandlrClient: guesses format")
 
+skip_on_cran()
+
 test_that("guesses correctly: citeproc", {
   z <- system.file("extdata/citeproc.json", package = "handlr")
   x <- HandlrClient$new(z)
diff --git a/tests/testthat/test-codemeta_reader.R b/tests/testthat/test-codemeta_reader.R
index 77b420c..c67d1dd 100644
--- a/tests/testthat/test-codemeta_reader.R
+++ b/tests/testthat/test-codemeta_reader.R
@@ -3,6 +3,8 @@ context("codemeta_reader")
 z <- system.file('extdata/codemeta.json', package = "handlr")
 
 test_that("codemeta_reader: works", {
+  skip_on_cran()
+
   x <- codemeta_reader(z)
 
   expect_is(codemeta_reader, "function")
@@ -16,6 +18,8 @@ test_that("codemeta_reader: works", {
 })
 
 test_that("codemeta_reader: read from string", {
+  skip_on_cran()
+  
   str <- paste0(readLines(z), collapse = "")
   x <- codemeta_reader(str)
   
diff --git a/tests/testthat/test-codemeta_writer.R b/tests/testthat/test-codemeta_writer.R
index 845008b..6a833fb 100644
--- a/tests/testthat/test-codemeta_writer.R
+++ b/tests/testthat/test-codemeta_writer.R
@@ -1,6 +1,8 @@
 context("codemeta_writer")
 
 test_that("codemeta_writer: works", {
+  skip_on_cran()
+
   z <- system.file('extdata/codemeta.json', package = "handlr")
   tmp <- codemeta_reader(z)
   x <- codemeta_writer(tmp)
@@ -11,6 +13,8 @@ test_that("codemeta_writer: works", {
 })
 
 test_that("codemeta_writer: write from citeproc json", {
+  skip_on_cran()
+
   z <- system.file('extdata/citeproc.json', package = "handlr")
   tmp <- citeproc_reader(z)
   x <- codemeta_writer(z = tmp)
@@ -20,6 +24,8 @@ test_that("codemeta_writer: write from citeproc json", {
 test_that("codemeta_writer: output gives back same as 
   input from codemeta_reader", {
 
+  skip_on_cran()
+
   z <- system.file('extdata/codemeta.json', package = "handlr")
   w <- codemeta_reader(z)
   bw_out <- codemeta_writer(w)
diff --git a/tests/testthat/test-handl-class.R b/tests/testthat/test-handl-class.R
index 7223439..3b17d4e 100644
--- a/tests/testthat/test-handl-class.R
+++ b/tests/testthat/test-handl-class.R
@@ -1,6 +1,8 @@
 context("handl-class")
 
 test_that("handl class", {
+  skip_on_cran()
+
   z <- system.file('extdata/crossref.bib', package = "handlr")
   x <- bibtex_reader(z)
 
diff --git a/tests/testthat/test-handl_to_df.R b/tests/testthat/test-handl_to_df.R
index 28af4bc..0f39ddc 100644
--- a/tests/testthat/test-handl_to_df.R
+++ b/tests/testthat/test-handl_to_df.R
@@ -1,6 +1,8 @@
 context("handl_to_df")
-# handl_to_df(handl_empty())
+
 test_that("handl_to_df: works", {
+  skip_on_cran()
+
   z <- system.file('extdata/crossref.bib', package = "handlr")
   x <- bibtex_reader(z)
   aa <- handl_to_df(x)
@@ -21,6 +23,8 @@ test_that("handl_to_df: works", {
 })
 
 test_that("handl_to_df: works with many citations", {
+  skip_on_cran()
+
   z <- system.file('extdata/bib-many.bib', package = "handlr")
   res2 <- bibtex_reader(x = z)
   aa <- handl_to_df(res2)
@@ -33,6 +37,8 @@ test_that("handl_to_df: works with many citations", {
 })
 
 test_that("handl_to_df: works with HandlrClient", {
+  skip_on_cran()
+  
   z <- system.file('extdata/bib-many.bib', package = "handlr")
   x <- HandlrClient$new(x = z)
   
diff --git a/tests/testthat/test-ris_reader.R b/tests/testthat/test-ris_reader.R
index c78fd35..9489c5e 100644
--- a/tests/testthat/test-ris_reader.R
+++ b/tests/testthat/test-ris_reader.R
@@ -1,6 +1,8 @@
 context("ris_reader")
 
 test_that("ris_reader: works", {
+  skip_on_cran()
+
   z <- system.file("extdata/crossref.ris", package = "handlr")
   x <- ris_reader(z)
 
@@ -25,6 +27,8 @@ test_that("ris_reader: works", {
 })
 
 test_that("ris_reader: many inputs", {
+  skip_on_cran()
+  
   z <- system.file("extdata/multiple-eg.ris", package = "handlr")
   x <- ris_reader(z)
 
diff --git a/tests/testthat/test-ris_writer.R b/tests/testthat/test-ris_writer.R
index 338260b..82fe396 100644
--- a/tests/testthat/test-ris_writer.R
+++ b/tests/testthat/test-ris_writer.R
@@ -1,6 +1,8 @@
 context("ris_writer")
 
 test_that("ris_writer: works", {
+  skip_on_cran()
+
   z <- system.file("extdata/crossref.ris", package = "handlr")
   tmp <- ris_reader(z)
   x <- ris_writer(tmp)
@@ -10,6 +12,8 @@ test_that("ris_writer: works", {
 })
 
 test_that("ris_writer: write from citeproc json", {
+  skip_on_cran()
+
   z <- system.file("extdata/citeproc.json", package = "handlr")
   tmp <- citeproc_reader(z)
   x <- ris_writer(tmp)
@@ -17,6 +21,8 @@ test_that("ris_writer: write from citeproc json", {
 })
 
 test_that("ris_writer: output gives back same as input from ris_reader", {
+  skip_on_cran()
+  
   z <- system.file("extdata/peerj.ris", package = "handlr")
   w <- ris_reader(z)
   bw_out <- ris_writer(w)