diff --git a/test/pdfs/protectip.pdf.link b/test/pdfs/protectip.pdf.link
index 1af1bd87..392e4592 100644
--- a/test/pdfs/protectip.pdf.link
+++ b/test/pdfs/protectip.pdf.link
@@ -1 +1 @@
-http://leahy.senate.gov/imo/media/doc/BillText-PROTECTIPAct.pdf
+https://web.archive.org/web/20150915183044/http://www.leahy.senate.gov/imo/media/doc/BillText-PROTECTIPAct.pdf
diff --git a/test/pdfs/tutorial.pdf.link b/test/pdfs/tutorial.pdf.link
index ec8141ce..62787c0a 100644
--- a/test/pdfs/tutorial.pdf.link
+++ b/test/pdfs/tutorial.pdf.link
@@ -1 +1 @@
-http://cplusplus.com/files/tutorial.pdf
+https://web.archive.org/web/20150915102004/http://www.cplusplus.com/files/tutorial.pdf
diff --git a/test/pdfs/txt2pdf.pdf.link b/test/pdfs/txt2pdf.pdf.link
index 09653f39..5eda75b4 100644
--- a/test/pdfs/txt2pdf.pdf.link
+++ b/test/pdfs/txt2pdf.pdf.link
@@ -1 +1 @@
-http://www.sanface.com/pdf/test.pdf
+https://web.archive.org/web/20150910131256/http://www.sanface.com/pdf/test.pdf
diff --git a/test/pdfs/unix01.pdf.link b/test/pdfs/unix01.pdf.link
index f8ad05e4..84d30ddb 100644
--- a/test/pdfs/unix01.pdf.link
+++ b/test/pdfs/unix01.pdf.link
@@ -1 +1 @@
-https://docs.rice.edu/confluence/download/attachments/4588376/unix01.pdf?version=1
+https://web.archive.org/web/20100606211934/https://docs.rice.edu/confluence/download/attachments/4588376/unix01.pdf?version=1
diff --git a/test/pdfs/usmanm-bad.pdf.link b/test/pdfs/usmanm-bad.pdf.link
index e37e5aa2..af488d20 100644
--- a/test/pdfs/usmanm-bad.pdf.link
+++ b/test/pdfs/usmanm-bad.pdf.link
@@ -1 +1 @@
-http://web.mit.edu/6.033/2011/wwwdocs/writing-samples/usmanm_dp1.pdf
+https://web.archive.org/web/20160107124830/http://web.mit.edu/6.033/2011/wwwdocs/writing-samples/usmanm_dp1.pdf