diff --git a/bin/tests/system/Makefile.in b/bin/tests/system/Makefile.in
index 1b7ff31dd7..cfd8e16d24 100644
--- a/bin/tests/system/Makefile.in
+++ b/bin/tests/system/Makefile.in
@@ -92,7 +92,7 @@ parallel.mk:
 	for directory in $(PARALLEL) ; do \
 		echo "" >> $@ ; \
 		echo "test-`echo $$directory | tr _ -`:" >> $@ ; \
-		echo "	@$(SHELL) ./run.sh $$NOCLEAN -r -p $$port $$directory 2>&1 | tee $$directory/test.output" >> $@ ; \
+		echo "	@$(SHELL) ./run.sh -r -p $$port $$directory 2>&1 | tee $$directory/test.output" >> $@ ; \
 		port=`expr $$port + 100` ; \
 	done
 
@@ -100,7 +100,7 @@ parallel.mk:
 
 test: parallel.mk subdirs
 	@$(MAKE) -f parallel.mk check
-	@$(SHELL) ./runsequential.sh $$NOCLEAN -r
+	@$(SHELL) ./runsequential.sh -r
 	@$(SHELL) ./testsummary.sh
 
 check: test
diff --git a/bin/tests/system/README b/bin/tests/system/README
index 4bf6719d44..3b521fc911 100644
--- a/bin/tests/system/README
+++ b/bin/tests/system/README
@@ -153,10 +153,10 @@ A run of all the system tests can also be initiated via make:
     make [-j numproc] test
 
 In this case, retention of the output files after a test completes successfully
-is specified by setting the environment variable NOCLEAN to "-n" prior to
-running make, e.g.
+is specified by setting the environment variable SYSTEMTEST_NO_CLEAN to 1 prior
+to running make, e.g.
 
-    NOCLEAN=-n make [-j numproc] test
+    SYSTEMTEST_NO_CLEAN=1 make [-j numproc] test
 
 
 
@@ -714,7 +714,7 @@ the ports are assigned when the tests are run.  This is achieved by having the
 when "make check" is run, and contains a target for each test of the form:
 
     <test-name>:
-        @$(SHELL) run.sh $$NOCLEAN -r -p <baseport> <test-name>
+        @$(SHELL) run.sh -r -p <baseport> <test-name>
 
 The <baseport> is unique and the values of <baseport> for each test are
 separated by at least 100 ports.
diff --git a/bin/tests/system/run.sh b/bin/tests/system/run.sh
index 60e6395da7..9abdedbba8 100644
--- a/bin/tests/system/run.sh
+++ b/bin/tests/system/run.sh
@@ -17,9 +17,14 @@ SYSTEMTESTTOP=.
 . $SYSTEMTESTTOP/conf.sh
 
 stopservers=true
-clean=true
 baseport=5300
 
+if [ ${SYSTEMTEST_NO_CLEAN:-0} -eq 1 ]; then
+	clean=false
+else
+	clean=true
+fi
+
 while getopts "knp:r" flag; do
     case "$flag" in
 	k) stopservers=false ;;
diff --git a/bin/tests/system/runall.sh b/bin/tests/system/runall.sh
index 5aa9412454..0ad6739527 100644
--- a/bin/tests/system/runall.sh
+++ b/bin/tests/system/runall.sh
@@ -27,12 +27,13 @@ SYSTEMTESTTOP=.
 
 usage="Usage: ./runall.sh [-n] [numprocesses]"
 
+SYSTEMTEST_NO_CLEAN=0
+
 # Handle "-n" switch if present.
 
-NOCLEAN=""
 while getopts "n" flag; do
     case "$flag" in
-        n) NOCLEAN="-n" ;;
+        n) SYSTEMTEST_NO_CLEAN=1 ;;
     esac
 done
 export NOCLEAN
@@ -57,6 +58,8 @@ fi
 
 # Run the tests.
 
+export SYSTEMTEST_NO_CLEAN
+
 status=0
 if [ "$CYGWIN" = "" ]; then
     # Running on Unix, use "make" to run tests in parallel.
@@ -69,7 +72,7 @@ else
     # used, the tests would be run sequentially anyway.)
     {
         for testdir in $SUBDIRS; do
-            $SHELL run.sh $NOCLEAN $testdir || status=1
+            $SHELL run.sh $testdir || status=1
         done
     } 2>&1 | tee "systests.output"
 fi