diff --git a/src/content_cao.cpp b/src/content_cao.cpp
index 5ddbd27c9..83756c963 100644
--- a/src/content_cao.cpp
+++ b/src/content_cao.cpp
@@ -604,7 +604,7 @@ bool GenericCAO::getCollisionBox(aabb3f *toset) const
 	return false;
 }
 
-bool GenericCAO::collideWithObjects()
+bool GenericCAO::collideWithObjects() const
 {
 	return m_prop.collideWithObjects;
 }
diff --git a/src/content_cao.h b/src/content_cao.h
index 19fecdde5..846e0690a 100644
--- a/src/content_cao.h
+++ b/src/content_cao.h
@@ -132,7 +132,7 @@ public:
 
 	bool getCollisionBox(aabb3f *toset) const;
 
-	bool collideWithObjects();
+	bool collideWithObjects() const;
 
 	aabb3f *getSelectionBox();