diff --git a/R/cpp11.R b/R/cpp11.R
index 91d92bdad..64ac5f377 100644
--- a/R/cpp11.R
+++ b/R/cpp11.R
@@ -172,6 +172,10 @@ rapi_rel_from_table_function <- function(con, function_name, positional_paramete
   .Call(`_duckdb_rapi_rel_from_table_function`, con, function_name, positional_parameters_sexps, named_parameters_sexps)
 }
 
+rapi_get_last_rel_mat <- function() {
+  .Call(`_duckdb_rapi_get_last_rel_mat`)
+}
+
 # allow_materialization = TRUE: compatibility with duckplyr <= 0.4.1
 rapi_rel_to_altrep <- function(rel, allow_materialization = TRUE) {
   .Call(`_duckdb_rapi_rel_to_altrep`, rel, allow_materialization)
diff --git a/src/cpp11.cpp b/src/cpp11.cpp
index b42b45ac2..fa0c76fda 100644
--- a/src/cpp11.cpp
+++ b/src/cpp11.cpp
@@ -315,6 +315,13 @@ extern "C" SEXP _duckdb_rapi_rel_from_table_function(SEXP con, SEXP function_nam
   END_CPP11
 }
 // reltoaltrep.cpp
+std::string rapi_get_last_rel_mat();
+extern "C" SEXP _duckdb_rapi_get_last_rel_mat() {
+  BEGIN_CPP11
+    return cpp11::as_sexp(rapi_get_last_rel_mat());
+  END_CPP11
+}
+// reltoaltrep.cpp
 SEXP rapi_rel_to_altrep(duckdb::rel_extptr_t rel, bool allow_materialization);
 extern "C" SEXP _duckdb_rapi_rel_to_altrep(SEXP rel, SEXP allow_materialization) {
   BEGIN_CPP11
@@ -445,6 +452,7 @@ static const R_CallMethodDef CallEntries[] = {
     {"_duckdb_rapi_expr_set_alias",          (DL_FUNC) &_duckdb_rapi_expr_set_alias,          2},
     {"_duckdb_rapi_expr_tostring",           (DL_FUNC) &_duckdb_rapi_expr_tostring,           1},
     {"_duckdb_rapi_expr_window",             (DL_FUNC) &_duckdb_rapi_expr_window,             9},
+    {"_duckdb_rapi_get_last_rel_mat",        (DL_FUNC) &_duckdb_rapi_get_last_rel_mat,        0},
     {"_duckdb_rapi_get_null_SEXP_ptr",       (DL_FUNC) &_duckdb_rapi_get_null_SEXP_ptr,       0},
     {"_duckdb_rapi_get_substrait",           (DL_FUNC) &_duckdb_rapi_get_substrait,           3},
     {"_duckdb_rapi_get_substrait_json",      (DL_FUNC) &_duckdb_rapi_get_substrait_json,      3},
diff --git a/src/reltoaltrep.cpp b/src/reltoaltrep.cpp
index 5408eb472..60cf9dc0b 100644
--- a/src/reltoaltrep.cpp
+++ b/src/reltoaltrep.cpp
@@ -338,6 +338,13 @@ static R_altrep_class_t LogicalTypeToAltrepType(const LogicalType &type) {
 	}
 }
 
+[[cpp11::register]] std::string rapi_get_last_rel_mat() {
+	if (!AltrepRelationWrapper::last_rel) {
+		return "";
+	}
+	return AltrepRelationWrapper::last_rel->ToString();
+}
+
 [[cpp11::register]] SEXP rapi_rel_to_altrep(duckdb::rel_extptr_t rel, bool allow_materialization) {
 	D_ASSERT(rel && rel->rel);
 	auto drel = rel->rel;