diff --git a/tests/compat.sh b/tests/compat.sh
index 1eea23c..0146e15 100755
--- a/tests/compat.sh
+++ b/tests/compat.sh
@@ -757,8 +757,8 @@
     SERVER_NAME=$1
 
     log "$SERVER_CMD"
-    echo "$SERVER_CMD" > srv_out
-    $SERVER_CMD >> srv_out 2>&1 &
+    echo "$SERVER_CMD" > $SRV_OUT
+    $SERVER_CMD >> $SRV_OUT 2>&1 &
     PROCESS_ID=$!
 
     sleep 1
@@ -787,19 +787,19 @@
     wait $PROCESS_ID 2>/dev/null
 
     if [ "$MEMCHECK" -gt 0 ]; then
-        if is_polar "$SERVER_CMD" && has_mem_err srv_out; then
+        if is_polar "$SERVER_CMD" && has_mem_err $SRV_OUT; then
             echo "  ! Server had memory errors"
             let "srvmem++"
             return
         fi
     fi
 
-    rm -f srv_out
+    rm -f $SRV_OUT
 }
 
 # kill the running server (used when killed by signal)
 cleanup() {
-    rm -f srv_out cli_out
+    rm -f $SRV_OUT $CLI_OUT
     kill $PROCESS_ID
     exit 1
 }
@@ -820,14 +820,14 @@
         [Oo]pen*)
             CLIENT_CMD="$OPENSSL_CMD s_client $O_CLIENT_ARGS -cipher $2"
             log "$CLIENT_CMD"
-            echo "$CLIENT_CMD" > cli_out
-            ( echo -e 'GET HTTP/1.0'; echo; ) | $CLIENT_CMD >> cli_out 2>&1
+            echo "$CLIENT_CMD" > $CLI_OUT
+            ( echo -e 'GET HTTP/1.0'; echo; ) | $CLIENT_CMD >> $CLI_OUT 2>&1
             EXIT=$?
 
             if [ "$EXIT" == "0" ]; then
                 RESULT=0
             else
-                if grep 'Cipher is (NONE)' cli_out >/dev/null; then
+                if grep 'Cipher is (NONE)' $CLI_OUT >/dev/null; then
                     RESULT=1
                 else
                     RESULT=2
@@ -838,8 +838,8 @@
         [Gg]nu*)
             CLIENT_CMD="$GNUTLS_CLI $G_CLIENT_ARGS --priority $G_PRIO_MODE:$2 localhost"
             log "$CLIENT_CMD"
-            echo "$CLIENT_CMD" > cli_out
-            ( echo -e 'GET HTTP/1.0'; echo; ) | $CLIENT_CMD >> cli_out 2>&1
+            echo "$CLIENT_CMD" > $CLI_OUT
+            ( echo -e 'GET HTTP/1.0'; echo; ) | $CLIENT_CMD >> $CLI_OUT 2>&1
             EXIT=$?
 
             if [ "$EXIT" == "0" ]; then
@@ -848,8 +848,8 @@
                 RESULT=2
                 # interpret early failure, with a handshake_failure alert
                 # before the server hello, as "no ciphersuite in common"
-                if grep -F 'Received alert [40]: Handshake failed' cli_out; then
-                    if grep -i 'SERVER HELLO .* was received' cli_out; then :
+                if grep -F 'Received alert [40]: Handshake failed' $CLI_OUT; then
+                    if grep -i 'SERVER HELLO .* was received' $CLI_OUT; then :
                     else
                         RESULT=1
                     fi
@@ -863,8 +863,8 @@
                 CLIENT_CMD="valgrind --leak-check=full $CLIENT_CMD"
             fi
             log "$CLIENT_CMD"
-            echo "$CLIENT_CMD" > cli_out
-            $CLIENT_CMD >> cli_out 2>&1
+            echo "$CLIENT_CMD" > $CLI_OUT
+            $CLIENT_CMD >> $CLI_OUT 2>&1
             EXIT=$?
 
             case $EXIT in
@@ -874,7 +874,7 @@
             esac
 
             if [ "$MEMCHECK" -gt 0 ]; then
-                if is_polar "$CLIENT_CMD" && has_mem_err cli_out; then
+                if is_polar "$CLIENT_CMD" && has_mem_err $CLI_OUT; then
                     RESULT=2
                 fi
             fi
@@ -887,7 +887,7 @@
             ;;
     esac
 
-    echo "EXIT: $EXIT" >> cli_out
+    echo "EXIT: $EXIT" >> $CLI_OUT
 
     # report and count result
     case $RESULT in
@@ -900,14 +900,14 @@
             ;;
         "2")
             echo FAIL
-            cp srv_out c-srv-${tests}.log
-            cp cli_out c-cli-${tests}.log
+            cp $SRV_OUT c-srv-${tests}.log
+            cp $CLI_OUT c-cli-${tests}.log
             echo "  ! outputs saved to c-srv-${tests}.log, c-cli-${tests}.log"
             let "failed++"
             ;;
     esac
 
-    rm -f cli_out
+    rm -f $CLI_OUT
 }
 
 #
@@ -956,6 +956,10 @@
 PORT="0000$$"
 PORT="1$(echo $PORT | tail -c 4)"
 
+# Also pick a unique name for intermediate files
+SRV_OUT="srv_out.$$"
+CLI_OUT="cli_out.$$"
+
 trap cleanup INT TERM HUP
 
 for VERIFY in $VERIFIES; do
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 4df999e..19be5ef 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -89,8 +89,8 @@
     echo "FAIL"
     echo "  ! $1"
 
-    cp srv_out o-srv-${TESTS}.log
-    cp cli_out o-cli-${TESTS}.log
+    cp $SRV_OUT o-srv-${TESTS}.log
+    cp $CLI_OUT o-cli-${TESTS}.log
     echo "  ! outputs saved to o-srv-${TESTS}.log and o-cli-${TESTS}.log"
 
     FAILS=`echo $FAILS + 1 | bc`
@@ -142,14 +142,14 @@
     fi
 
     # run the commands
-    echo "$SRV_CMD" > srv_out
-    $SRV_CMD >> srv_out 2>&1 &
+    echo "$SRV_CMD" > $SRV_OUT
+    $SRV_CMD >> $SRV_OUT 2>&1 &
     SRV_PID=$!
     sleep 1
-    echo "$CLI_CMD" > cli_out
-    eval "$CLI_CMD" >> cli_out 2>&1
+    echo "$CLI_CMD" > $CLI_OUT
+    eval "$CLI_CMD" >> $CLI_OUT 2>&1
     CLI_EXIT=$?
-    echo "EXIT: $CLI_EXIT" >> cli_out
+    echo "EXIT: $CLI_EXIT" >> $CLI_OUT
 
     # psk is useful when server only has bad certs
     if is_polar "$SRV_CMD"; then
@@ -166,14 +166,14 @@
     # expected client exit to incorrectly succeed in case of catastrophic
     # failure)
     if is_polar "$SRV_CMD"; then
-        if grep "Performing the SSL/TLS handshake" srv_out >/dev/null; then :;
+        if grep "Performing the SSL/TLS handshake" $SRV_OUT >/dev/null; then :;
         else
             fail "server failed to start"
             return
         fi
     fi
     if is_polar "$CLI_CMD"; then
-        if grep "Performing the SSL/TLS handshake" cli_out >/dev/null; then :;
+        if grep "Performing the SSL/TLS handshake" $CLI_OUT >/dev/null; then :;
         else
             fail "client failed to start"
             return
@@ -199,28 +199,28 @@
     do
         case $1 in
             "-s")
-                if grep "$2" srv_out >/dev/null; then :; else
+                if grep "$2" $SRV_OUT >/dev/null; then :; else
                     fail "-s $2"
                     return
                 fi
                 ;;
 
             "-c")
-                if grep "$2" cli_out >/dev/null; then :; else
+                if grep "$2" $CLI_OUT >/dev/null; then :; else
                     fail "-c $2"
                     return
                 fi
                 ;;
 
             "-S")
-                if grep "$2" srv_out >/dev/null; then
+                if grep "$2" $SRV_OUT >/dev/null; then
                     fail "-S $2"
                     return
                 fi
                 ;;
 
             "-C")
-                if grep "$2" cli_out >/dev/null; then
+                if grep "$2" $CLI_OUT >/dev/null; then
                     fail "-C $2"
                     return
                 fi
@@ -235,11 +235,11 @@
 
     # check valgrind's results
     if [ "$MEMCHECK" -gt 0 ]; then
-        if is_polar "$SRV_CMD" && has_mem_err srv_out; then
+        if is_polar "$SRV_CMD" && has_mem_err $SRV_OUT; then
             fail "Server has memory errors"
             return
         fi
-        if is_polar "$CLI_CMD" && has_mem_err cli_out; then
+        if is_polar "$CLI_CMD" && has_mem_err $CLI_OUT; then
             fail "Client has memory errors"
             return
         fi
@@ -247,11 +247,11 @@
 
     # if we're here, everything is ok
     echo "PASS"
-    rm -f srv_out cli_out
+    rm -f $SRV_OUT $CLI_OUT
 }
 
 cleanup() {
-    rm -f cli_out srv_out sess
+    rm -f $CLI_OUT $SRV_OUT $SESSION
     kill $SRV_PID
     exit 1
 }
@@ -286,6 +286,11 @@
 O_SRV="$O_SRV -accept $PORT"
 O_CLI="$O_CLI -connect localhost:$PORT"
 
+# Also pick a unique name for intermediate files
+SRV_OUT="srv_out.$$"
+CLI_OUT="cli_out.$$"
+SESSION="session.$$"
+
 trap cleanup INT TERM HUP
 
 # Test for SSLv2 ClientHello
@@ -374,7 +379,9 @@
 
 run_test    "Session resume using tickets #5 (openssl client)" \
             "$P_SRV debug_level=4 tickets=1" \
-            "($O_CLI -sess_out sess; $O_CLI -sess_in sess; rm -f sess)" \
+            "( $O_CLI -sess_out $SESSION; \
+               $O_CLI -sess_in $SESSION; \
+               rm -f $SESSION )" \
             0 \
             -s "found session ticket extension" \
             -s "server hello, adding session ticket extension" \
@@ -459,7 +466,9 @@
 
 run_test    "Session resume using cache #8 (openssl client)" \
             "$P_SRV debug_level=4 tickets=0" \
-            "($O_CLI -sess_out sess; $O_CLI -sess_in sess; rm -f sess)" \
+            "( $O_CLI -sess_out $SESSION; \
+               $O_CLI -sess_in $SESSION; \
+               rm -f $SESSION )" \
             0 \
             -s "found session ticket extension" \
             -S "server hello, adding session ticket extension" \