diff --git a/.unreleased/bug-fixes/sany-tmpdir.md b/.unreleased/bug-fixes/sany-tmpdir.md
new file mode 100644
index 0000000000..8cce6d77c8
--- /dev/null
+++ b/.unreleased/bug-fixes/sany-tmpdir.md
@@ -0,0 +1 @@
+Add extra protection against the SANY race conditions on the filesystem, see #3046
diff --git a/src/universal/bin/apalache-mc b/src/universal/bin/apalache-mc
index 45b2f28f73..e9e5dfc32f 100755
--- a/src/universal/bin/apalache-mc
+++ b/src/universal/bin/apalache-mc
@@ -38,16 +38,24 @@ then
     JVM_ARGS="${JVM_ARGS} -Xmx4096m"
 fi
 
+# Avoid SANY concurrency issues: https://github.com/tlaplus/tlaplus/issues/688
+if [ -z "${TMPDIR:-}" ]; then
+    TMPDIR="$(pwd)/tmp"
+    mkdir -p "$TMPDIR"
+fi
+JAVA_IO_TMPDIR=`mktemp -d -t SANYXXXXXXXXXX`
+
 # Check whether the CLI args contains the debug flag
 if [[ "$*" =~ '--debug' ]]
 then
     echo "# Tool home: $DIR"
     echo "# Package:   $APALACHE_JAR"
     echo "# JVM args: $JVM_ARGS"
+    echo "# -Djava.io.tmpdir: $JAVA_IO_TMPDIR"
     echo "#"
 fi
 
 # Run with `exec` to replace the PID, rather than running in a subshell.
 # This saves one process, and ensures signals are sent to the replacement process
 # C.f. https://github.com/sbt/sbt-native-packager/blob/e72f2f45b8cab5881add1cd62743bfc69c2b9b4d/src/main/resources/com/typesafe/sbt/packager/archetypes/scripts/bash-template#L141-L142
-exec java $JVM_ARGS -jar "$APALACHE_JAR" "$@"
+exec java $JVM_ARGS -Djava.io.tmpdir=$JAVA_IO_TMPDIR -jar "$APALACHE_JAR" "$@"