diff --git a/lib/node.ks b/lib/node.ks
index f6cc24f..d721fd9 100644
--- a/lib/node.ks
+++ b/lib/node.ks
@@ -24,15 +24,6 @@ function estimated_burn_duration {
 }
 
 
-function estimated_rcs_burn_duration {
-    //
-    // Calculate estimated burn duration of a vector or node using RCS thrusters instead of main engines.
-    //
-    parameter burn.
-    return estimated_burn_duration(burn, rcs_isp_sum(), rcs_maxthrust()).
-}
-
-
 function vector_to_node {
     //
     // Convert given vector to a maneuver node, optionally at the given time.
diff --git a/lib/rcs.ks b/lib/rcs.ks
index 27a2c7c..9260ba8 100644
--- a/lib/rcs.ks
+++ b/lib/rcs.ks
@@ -1,5 +1,6 @@
 @LAZYGLOBAL off.
 
+run once "lib/node".
 run once "lib/target".
 run once "lib/vectors".
 
@@ -39,6 +40,15 @@ function rcs_maxthrust {
 }
 
 
+function rcs_estimated_burn_duration {
+    //
+    // Calculate estimated burn duration of a vector or node using RCS thrusters instead of main engines.
+    //
+    parameter burn.
+    return estimated_burn_duration(burn, rcs_isp_sum(), rcs_maxthrust()).
+}
+
+
 function rcs_translate {
     //
     // Translate the ship's position by the given vector using RCS thrusters.