diff --git a/src/lib/icu/Collate.cxx b/src/lib/icu/Collate.cxx
index 95c4316b3..84f54fe61 100644
--- a/src/lib/icu/Collate.cxx
+++ b/src/lib/icu/Collate.cxx
@@ -72,6 +72,7 @@ IcuCollateFinish() noexcept
 	assert(collator != nullptr);
 
 	ucol_close(collator);
+	collator = nullptr;
 }
 
 #endif