diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c
index 928552d551..91f1059e4c 100644
--- a/src/backend/utils/adt/jsonb.c
+++ b/src/backend/utils/adt/jsonb.c
@@ -2148,7 +2148,16 @@ jsonb_float8(PG_FUNCTION_ARGS)
 	JsonbValue	v;
 	Datum		retValue;
 
-	if (!JsonbExtractScalar(&in->root, &v) || v.type != jbvNumeric)
+	if (!JsonbExtractScalar(&in->root, &v))
+		cannotCastJsonbValue(v.type, "double precision");
+
+	if (v.type == jbvNull)
+	{
+		PG_FREE_IF_COPY(in, 0);
+		PG_RETURN_NULL();
+	}
+
+	if (v.type != jbvNumeric)
 		cannotCastJsonbValue(v.type, "double precision");
 
 	retValue = DirectFunctionCall1(numeric_float8,