diff --git a/test/pdfs/issue1878.pdf.link b/test/pdfs/issue1878.pdf.link
index cc3519d65..c95895c60 100644
--- a/test/pdfs/issue1878.pdf.link
+++ b/test/pdfs/issue1878.pdf.link
@@ -1 +1 @@
-http://www.iau.org/static/scientific_meetings/postmr12.pdf
+http://web.archive.org/web/20150317000520/http://iau.org/static/scientific_meetings/postmr12.pdf
diff --git a/test/pdfs/issue1912.pdf.link b/test/pdfs/issue1912.pdf.link
index 3eade450a..ca29c1ba0 100644
--- a/test/pdfs/issue1912.pdf.link
+++ b/test/pdfs/issue1912.pdf.link
@@ -1 +1 @@
-http://rua.ua.es/dspace/bitstream/10045/23475/1/OBETS_07_01_03.pdf
+http://web.archive.org/web/20160115171702/http://rua.ua.es/dspace/bitstream/10045/23475/1/OBETS_07_01_03.pdf
diff --git a/test/pdfs/issue1936.pdf.link b/test/pdfs/issue1936.pdf.link
index 198c7a0a4..2ba8aceea 100644
--- a/test/pdfs/issue1936.pdf.link
+++ b/test/pdfs/issue1936.pdf.link
@@ -1,2 +1 @@
-http://sci2s.ugr.es/keel/pdf/specific/articulo/alp99.pdf
-
+http://web.archive.org/web/20091223123331/http://sci2s.ugr.es/keel/pdf/specific/articulo/alp99.pdf
diff --git a/test/pdfs/issue1998.pdf.link b/test/pdfs/issue1998.pdf.link
index 0a2ba6b07..514c67778 100644
--- a/test/pdfs/issue1998.pdf.link
+++ b/test/pdfs/issue1998.pdf.link
@@ -1 +1 @@
-http://www.uctc.net/access/30/Access%2030%20-%2002%20-%20Horse%20Power.pdf
\ No newline at end of file
+http://web.archive.org/web/20150223193848/http://www.uctc.net/access/30/Access%2030%20-%2002%20-%20Horse%20Power.pdf
diff --git a/test/pdfs/issue2006.pdf.link b/test/pdfs/issue2006.pdf.link
index ca0827725..6f1792d30 100644
--- a/test/pdfs/issue2006.pdf.link
+++ b/test/pdfs/issue2006.pdf.link
@@ -1 +1 @@
-http://pages.sencha.com/rs/sencha/images/Sencha-WP-Dev-Mgrs-Guide-to-HTML5.pdf
+http://web.archive.org/web/20150905181422/http://pages.sencha.com/rs/sencha/images/Sencha-WP-Dev-Mgrs-Guide-to-HTML5.pdf