diff --git a/tools/rpi-eeprom-digest b/tools/rpi-eeprom-digest
index d25f0ef..1a2dbe8 100755
--- a/tools/rpi-eeprom-digest
+++ b/tools/rpi-eeprom-digest
@@ -7,7 +7,7 @@
 
 set -e
 
-OPENSSL=${OPENSSl:-openssl}
+OPENSSL=${OPENSSL:-openssl}
 
 die() {
    echo "$@" >&2