diff --git a/src/geoarrow/metadata.c b/src/geoarrow/metadata.c
index 2afa470..536767c 100644
--- a/src/geoarrow/metadata.c
+++ b/src/geoarrow/metadata.c
@@ -552,7 +552,7 @@ int64_t GeoArrowUnescapeCrs(struct GeoArrowStringView crs, char* out, int64_t n)
     if (n > crs.size_bytes) {
       memcpy(out, crs.data, crs.size_bytes);
       out[crs.size_bytes] = '\0';
-    } else {
+    } else if (out != NULL) {
       memcpy(out, crs.data, n);
     }