diff --git a/README.md b/README.md
index c9676ac8..2ce850e0 100644
--- a/README.md
+++ b/README.md
@@ -752,8 +752,9 @@ Environment Variables used by test suite
 
 | Variable        | Default | Platforms | Purpose |
 |:--                 |:--        |:--     |:-- |
-| EXIV2_BINDIR       | **\<exiv2dir\>/build/bin** | All Platforms | Locatation of built binary object (exiv2.exe) |
-| EXIV2_EXT          | **.exe**  | msvc<br>Cygwin<br>Msys<br>MinGW | Extension used by executable binaries |
+| EXIV2_BINDIR       | **\<exiv2dir\>/build/bin** | All Platforms | Location of built binary objects (exiv2.exe) |
+| EXIV2_PORT         | **1276**  | All Platforms | Test TCP/IP Port   |
+| EXIV2_EXT          | **.exe**  | msvc<br>Cygwin<br>MinGW/msys2 | Extension used by executable binaries |
 | EXIV2_EXT          | _**not set**_  | Linux<br>macOS<br>Unix|  |
 | EXIV2_ECHO          | _**not set**_ | All Platforms | For debugging Bash scripts |
 | VALGRIND            | _**not set**_ | All Platforms | For debugging Bash scripts |
@@ -1167,4 +1168,4 @@ $ sudo pkg install developer/gcc-7
 
 [TOC](#TOC)
 
-Written by Robin Mills<br>robin@clanmills.com<br>Updated: 2020-04-21
+Written by Robin Mills<br>robin@clanmills.com<br>Updated: 2020-04-23
diff --git a/test/iotest.sh b/test/iotest.sh
index aab63809..a25c8534 100755
--- a/test/iotest.sh
+++ b/test/iotest.sh
@@ -21,18 +21,20 @@ source ./functions.source
 
 # Test http I/O
 (   cd "${testdir}/.."                                # testdir is the tmp output directory
+
     >&2 printf "*** HTTP tests begin\n"
-	port=9999
+    if [ ! -z $EXIV2_PORT ]; then port=EXIV2_PORT ; else port=1276; fi
 	url=http://0.0.0.0:$port
 	python3 -m http.server $port 2>&1 > /dev/null &   # start a background local HTTP server in the "real" test directory
     sleep 2                                           # wait for it to init
+
 	cd "$testdir"
     test_files="table.jpg Reagan.tiff exiv2-bug922a.jpg"
     for i in $test_files; do
     	runTest exiv2 -pa -g City -g DateTime $url/data/$i
     done
-    >&2 printf "*** HTTP tests end\n"
     kill $!                                           # kill the server
+    >&2 printf "*** HTTP tests end\n"
 
 )  | tr -d '\r' | sed 's/[ \t]+$//' > $results
 reportTest