diff --git a/test/run-tests.sh b/test/run-tests.sh
index 401f7784b03c1468591d12b47f8f11830430af99..87b0f13245419bd6fed716a35365e4b727cc3350 100755
--- a/test/run-tests.sh
+++ b/test/run-tests.sh
@@ -12,11 +12,16 @@ usage () {
     echo " - quit with exit status >0 if an unhandled error occurs"
     echo " you need to supply the .script in the second argument"
     echo " lisps include abcl, ccl (clozure),"
-    echo " allegro, allegro8, allegromodern, allegromodern8,"
-    echo " allegro_s, allegro8_s, allegromodern_s, allegromodern8_s (SMP variants)"
-    echo " allegro_64, allegro8_64, allegromodern_64, allegromodern8_64 (64-bit variants),"
-    echo " allegro_64_S, allegro8_64_S, allegromodern_64_S, allegromodern8_64_S, (SMP, 64-bit variants)"
-    echo " clisp, cmucl, ecl, gcl, sbcl, scl and xcl."
+    echo "    allegro, allegro8, allegromodern, allegromodern8,"
+    echo "    allegro_s, allegro8_s, allegromodern_s, allegromodern8_s (SMP variants)"
+    echo "    allegro_64, allegro8_64, allegromodern_64, allegromodern8_64 (64-bit variants),"
+    echo "    allegro_64_S, allegro8_64_S, allegromodern_64_S, allegromodern8_64_S, (SMP, 64-bit variants)"
+    echo "    clisp, cmucl, ecl, gcl, sbcl, scl and xcl."
+    echo " To configure the script, you may set environment variables to point to the various lisp runtimes."
+    echo " Allegro CL is a special case: instead of setting environment variables for the specific runtime"
+    echo "   locations, you may simply specify the Allegro install directories using these variables:"
+    echo "     ALLEGRO64DIR, ALLEGRO64SDIR (64-bit Allegro and SMP Allegro, respectively), ALLEGRODIR, and"
+    echo "     ALLEGROSDIR."
     echo "OPTIONS:"
     echo "    -d -- debug mode"
     echo "    -h -- show this message."
@@ -31,6 +36,32 @@ unset DEBUG_ASDF_TEST upgrade clean_load load_systems test_interactively extract
 SHELL=/bin/sh
 export SHELL DEBUG_ASDF_TEST GCL_ANSI ASDF_OUTPUT_TRANSLATIONS
 
+if [ $ALLEGRO64DIR ] ; then
+    ALLEGRO_64=${ALLEGRO64DIR}/alisp
+    ALLEGRO8_64=${ALLEGRO64DIR}/alisp8
+    ALLEGROMODERN_64=${ALLEGRO64DIR}/mlisp
+    ALLEGROMODERN8_64=${ALLEGRO64DIR}/mlisp8
+fi
+if [ $ALLEGRO64SDIR ] ; then
+    ALLEGRO_64_S=${ALLEGRO64SDIR}/alisp
+    ALLEGRO8_64_S=${ALLEGRO64SDIR}/alisp8
+    ALLEGROMODERN_64_S=${ALLEGRO64SDIR}/mlisp
+    ALLEGROMODERN8_64_S=${ALLEGRO64SDIR}/mlisp8
+fi
+if [ $ALLEGRODIR ] ; then
+    ALLEGRO=${ALLEGRODIR}/alisp
+    ALLEGRO8=${ALLEGRODIR}/alisp8
+    ALLEGROMODERN=${ALLEGRODIR}/mlisp
+    ALLEGROMODERN8=${ALLEGRODIR}/mlisp8
+fi
+if [ $ALLEGROSDIR ] ; then
+    ALLEGRO_S=${ALLEGROSDIR}/alisp
+    ALLEGRO8_S=${ALLEGROSDIR}/alisp8
+    ALLEGROMODERN_S=${ALLEGROSDIR}/mlisp
+    ALLEGROMODERN8_S=${ALLEGROSDIR}/mlisp8
+fi
+
+
 while getopts "cdtHulhu" OPTION
 do
     case $OPTION in