diff --git a/bin/octocatalog-diff b/bin/octocatalog-diff
--- a/bin/octocatalog-diff
+++ b/bin/octocatalog-diff
@@ -7,7 +7,7 @@
 FACTS_DIR="${OCD_BASE}/facts"
 
 function usage {
-    echo "usage: $0 [-f/--from from_branch] [-t/--to to_branch] [--no-clean-tmp] [--r10k-args r10k-args] [--octocatalog-diff-args octocatalog-diff-args] host1 host2 ..."
+    echo "usage: $0 [-f/--from from_branch] [-t/--to to_branch] [--no-clean-tmp] [--r10k-args r10k-args] [--octocatalog-diff-args octocatalog-diff-args] [--environment environment] host1 host2 ..."
 }
 
 CLEAN_TMPDIR=true
@@ -17,6 +17,7 @@
 HOSTS=()
 OCTOCATALOG_DIFF_ARGS=
 R10K_ARGS=
+PUPPET_ENVIRONMENT=production
 
 while (( "$#" )); do
     case "$1" in
@@ -28,6 +29,10 @@
             TO=$2
             shift
             ;;
+        --environment)
+            PUPPET_ENVIRONMENT=$2
+            shift
+            ;;
         --no-clean-tmp)
             CLEAN_TMPDIR=false
             ;;
@@ -127,6 +132,7 @@
         octocatalog-diff \
           --bootstrapped-from-dir $TMPDIR/environments/$FROM \
           --bootstrapped-to-dir $TMPDIR/environments/$TO \
+          --environment $PUPPET_ENVIRONMENT \
           -n $host \
           --display-detail-add \
           $OCTOCATALOG_DIFF_ARGS