diff --git a/changelog b/changelog
index 6d263d0b7cc..a914426f7b1 100644
--- a/changelog
+++ b/changelog
@@ -189,6 +189,7 @@ Version 1.13.1+dev:
    * Fixed bug 23060: unit stat tooltips do not show.
    * wmllint, wmlscope, wmlindent and wmllint-1.4 now run on Python 3
    * Text boxes tab completion now lists friends and whisperer nicks for easier answer (bug #9742)
+   * Avoid crash when planning moves on planned recruits (bug #18637)
    * Fixed cases of wrong unit type used in planning moves (bug #20299)
    * Fixed hang when attempting to make a screenshot from a non-existent map via
      command-line (bug #20900)
diff --git a/src/whiteboard/move.cpp b/src/whiteboard/move.cpp
index 2ee52b6e629..88368e23058 100644
--- a/src/whiteboard/move.cpp
+++ b/src/whiteboard/move.cpp
@@ -144,6 +144,13 @@ move::move(config const& cfg, bool hidden)
 
 void move::init()
 {
+	// If a unit is invalid, return immediately to avoid crashes such as trying to plan a move for a planned recruit.
+	// As per Bug #18637, this should be fixed so that planning moves on planned recruits work properly.
+	// The alternative is to disable movement on planned recruits altogether,
+	// possibly in select_or_action() where the fake unit is selected in the first place.
+	if (get_unit() == NULL)
+		return;
+
 	assert(get_unit());
 	unit_id_ = get_unit()->id();