diff --git a/samples/Makefile b/samples/Makefile
index d1b06c4..69bf8c7 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -4,8 +4,10 @@ RM=rm -f
 CMP=:
 ECHO=echo
 PYTHON=python2
+PYTHON3=python3
 
 PDF2TXT=PYTHONPATH=.. $(PYTHON) ../tools/pdf2txt.py -p1 -V
+PDF2TXT3=PYTHONPATH=.. $(PYTHON3) ../tools/pdf2txt.py -p1 -V
 
 FREE= \
 	simple1 \
@@ -45,6 +47,12 @@ tests:
 		$(CMP) $$i.xml $$i.xml.ref || exit 1; \
 		$(PDF2TXT) -t text -o $$i.txt $$i.pdf || eixt 1; \
 		$(CMP) $$i.txt $$i.txt.ref || exit 1; \
+		$(PDF2TXT3) -t html -o $$i.html $$i.pdf || exit 1; \
+		$(CMP) $$i.html $$i.html.ref || exit 1; \
+		$(PDF2TXT3) -t xml -o $$i.xml $$i.pdf || exit 1; \
+		$(CMP) $$i.xml $$i.xml.ref || exit 1; \
+		$(PDF2TXT3) -t text -o $$i.txt $$i.pdf || eixt 1; \
+		$(CMP) $$i.txt $$i.txt.ref || exit 1; \
 	done
 
 crypts:
@@ -54,6 +62,10 @@ crypts:
 		$(CMP) $$i.1.xml $(CRYPT_BASE).xml || exit 1; \
 		$(PDF2TXT) -t xml -P $(CRYPT_PASS2) -o $$i.2.xml $$i.pdf || exit 1; \
 		$(CMP) $$i.2.xml $(CRYPT_BASE).xml || exit 1; \
+		$(PDF2TXT3) -t xml -P $(CRYPT_PASS1) -o $$i.1.xml $$i.pdf || exit 1; \
+		$(CMP) $$i.1.xml $(CRYPT_BASE).xml || exit 1; \
+		$(PDF2TXT3) -t xml -P $(CRYPT_PASS2) -o $$i.2.xml $$i.pdf || exit 1; \
+		$(CMP) $$i.2.xml $(CRYPT_BASE).xml || exit 1; \
 	done
 
 test: