diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index c83d7e1..529734a 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -22,7 +22,8 @@
 -h/--help       -- print this text and exit
 --timeout TIMEOUT
                 -- dump the traceback and exit if a test takes more
-                   than TIMEOUT seconds
+                   than TIMEOUT seconds; disabled if TIMEOUT is negative
+                   or equals to zero
 --wait          -- wait for user input, e.g., allow a debugger to be attached
 
 Verbosity
@@ -420,8 +421,7 @@
                 sys.exit(1)
             timeout = float(a)
             if timeout <= 0:
-                print("The timeout must be greater than 0", file=sys.stderr)
-                sys.exit(1)
+                timeout = None
         elif o == '--wait':
             input("Press any key to continue...")
         else:
diff --git a/Makefile.pre.in b/Makefile.pre.in
index cd5a0f6..07486fd 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -755,9 +755,10 @@
 # generated bytecode.  This is sometimes a very shy bug needing a lot of
 # sample data.
 
-TESTOPTS=	-l --timeout=3600 $(EXTRATESTOPTS)
+TESTOPTS=	-l $(EXTRATESTOPTS)
 TESTPROG=	$(srcdir)/Lib/test/regrtest.py
 TESTPYTHON=	$(RUNSHARED) ./$(BUILDPYTHON) -Wd -E -bb $(TESTPYTHONOPTS)
+TESTTIMEOUT=	3600
 test:		all platform
 		-find $(srcdir)/Lib -name '*.py[co]' -print | xargs rm -f
 		-$(TESTPYTHON) $(TESTPROG) $(TESTOPTS)
@@ -789,7 +790,7 @@
 		-@if which pybuildbot.identify >/dev/null 2>&1; then \
 			pybuildbot.identify "CC='$(CC)'" "CXX='$(CXX)'"; \
 		fi
-		$(TESTPYTHON) $(TESTPROG) -uall -rwW $(TESTOPTS)
+		$(TESTPYTHON) $(TESTPROG) -uall -rwW --timeout=$(TESTTIMEOUT) $(TESTOPTS)
 
 QUICKTESTOPTS=	$(TESTOPTS) -x test_subprocess test_io test_lib2to3 \
 		test_multibytecodec test_urllib2_localnet test_itertools \