diff --git a/spcd/bootstrap.sh b/spcd/bootstrap.sh
index ebc7ac9..9521e7a 100644
--- a/spcd/bootstrap.sh
+++ b/spcd/bootstrap.sh
@@ -199,12 +199,12 @@ _SPCD_RULE_RIGHT="╴"
 # │ internal │ step │
 # ╰──────────┴──────╯
 
-SPCD_STEP_LEVEL=1
+_SPCD_STEP_LEVEL=1
 
 spcd_step_wipe() {
     unset \
-        "SPCD_STEP_${SPCD_STEP_LEVEL}_INDEX" \
-        "SPCD_STEP_${SPCD_STEP_LEVEL}_LABEL"
+        "SPCD_STEP_${_SPCD_STEP_LEVEL}_INDEX" \
+        "SPCD_STEP_${_SPCD_STEP_LEVEL}_LABEL"
 }
 
 #╶──────────────────────────────────────╴
@@ -371,7 +371,7 @@ spcd_split() {
 
 spcd_step() {
     if [ -n "${1}" ]; then
-        spcd_step__prefix="SPCD_STEP_${SPCD_STEP_LEVEL}"
+        spcd_step__prefix="SPCD_STEP_${_SPCD_STEP_LEVEL}"
         spcd_step__index="${spcd_step__prefix}_INDEX"
         eval "${spcd_step__index}=\$((${spcd_step__index} + 1))"
         eval "${spcd_step__prefix}_LABEL=\"${1}\""
@@ -381,13 +381,13 @@ spcd_step() {
 
 spcd_step_in() {
     [ -n "${1}" ] && spcd_step "${1}"
-    SPCD_STEP_LEVEL=$((SPCD_STEP_LEVEL + 1))
+    _SPCD_STEP_LEVEL=$((_SPCD_STEP_LEVEL + 1))
     spcd_step_wipe
 }
 
 spcd_step_out() {
     spcd_step_wipe
-    SPCD_STEP_LEVEL=$((SPCD_STEP_LEVEL - 1))
+    _SPCD_STEP_LEVEL=$((_SPCD_STEP_LEVEL - 1))
 }
 
 #╶──────────────────────────────────────╴