diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 074294cbcc..82a14295ee 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -4218,8 +4218,8 @@ numeric_poly_combine(PG_FUNCTION_ARGS)
 		state1->sumX = state2->sumX;
 		state1->sumX2 = state2->sumX2;
 #else
-		accum_sum_copy(&state2->sumX, &state1->sumX);
-		accum_sum_copy(&state2->sumX2, &state1->sumX2);
+		accum_sum_copy(&state1->sumX, &state2->sumX);
+		accum_sum_copy(&state1->sumX2, &state2->sumX2);
 #endif
 
 		MemoryContextSwitchTo(old_context);