diff --git a/src/library/compiler/csimp.cpp b/src/library/compiler/csimp.cpp
index b688bf6319..71b86c0434 100644
--- a/src/library/compiler/csimp.cpp
+++ b/src/library/compiler/csimp.cpp
@@ -330,7 +330,6 @@ class csimp_fn {
     };
 
     void collect_cases_info(expr e, cases_info_result & result) {
-        lean_assert(m_before_erasure);
         while (true) {
             if (is_lambda(e))
                 e = binding_body(e);