diff --git a/bin/env b/bin/env
new file mode 100644
index 0000000000000000000000000000000000000000..aa53f72eac19c8ef9936add790c94f866322bab9
--- /dev/null
+++ b/bin/env
@@ -0,0 +1 @@
+export BFAHOME=${HOME}/bfa
diff --git a/bin/explorer.sh b/bin/explorer.sh
index d1a37636ac5ba6462e6b517102439c0859104899..f59d45a3f12acd5a0b6c88c403f198499181782f 100755
--- a/bin/explorer.sh
+++ b/bin/explorer.sh
@@ -1,6 +1,12 @@
 #!/bin/bash
 # 20180619 Robert Martin-Legene <robert@nic.ar>
 
+if [ ! -d "${BFAHOME}" ]
+then
+    echo "\$BFAHOME does not point to a directory. Did you source \$BFAHOME/bin/env ?" >&2
+    exit 1
+fi
+
 trap "echo Argh;exit 1" ERR
 rpcport=8545