diff --git a/zcutil/fetch-params.sh b/zcutil/fetch-params.sh
index 392f60a2..54c46d3a 100755
--- a/zcutil/fetch-params.sh
+++ b/zcutil/fetch-params.sh
@@ -2,7 +2,7 @@
 
 set -eu
 
-PARAMS_DIR="$HOME/.zcash-params"
+PARAMS_DIR=${PARAMS_DIR:-$HOME/.zcash-params}
 
 SPROUT_PKEY_NAME='sprout-proving.key'
 SPROUT_VKEY_NAME='sprout-verifying.key'