Redshift won't change column type

Question

I'm trying to change a column in Redshift from varchar to integer. I've already checked and the strings are all numbers so it should force fine.

When I run:

alter table schema.table_name alter column "id" type int;

I get the following error:

ERROR: target data type "int8" is not supported [SQL State=0A000]

I've checked the Redshift documentation and just to rule out a few potentials:

• The field is not a primary or foreign key
• There's no compression encodings on it
• There's no default values
• The code is not in a transaction block

Any pointers would be amazing, thank you!