diff --git a/README.md b/README.md
index a4df3fd..1b6c816 100644
--- a/README.md
+++ b/README.md
@@ -198,7 +198,7 @@ if err != nil {
 }
 ```
 
-Having multiple statements in the same call is supported by the **pq** driver, so long as the statements do not contain any placeholder parameters. If they do contain placeholder parameters, then you'll receive the following error message at runtime:
+Having multiple statements in the same call is supported by the **pq** driver, _so long as the statements do not contain any placeholder parameters_. If they do contain placeholder parameters, then you'll receive the following error message at runtime:
 
 ```bash
 pq: cannot insert multiple commands into a prepared statement
@@ -206,6 +206,24 @@ pq: cannot insert multiple commands into a prepared statement
 
 To work around this, you will need to either split out the statements into separate database calls, or if that's not possible, you can create a [custom function](https://www.postgresql.org/docs/current/xfunc-sql.html) in PostgreSQL which acts as a wrapper around the multiple SQL statements that you want to run.
 
+### Why not use an unsigned integer for the movie ID?
+
+The first reason is that PostgreSQL doesn't have unsigned integers. Instead, it's best to align the integer types based on the following table :
+
+| PostgreSQL type       | Go type                                             | 
+|-----------------------|-----------------------------------------------------|
+| smallint, smallserial | int16 (-32768 to 32767)                             |
+| integer, serial       | int32 (-2147483648 to 2147483647)                   |
+| bigint, bigserial     | int64 (-9223372036854775808 to 9223372036854775807) |
+
+The second reason is that Go's **database/sql** package doesn't actually support any integer values greater than 9223372036854775807 (the maximum value for an **int64**). It’s possible that a **uint64** value could be greater than this, which would in turn lead to Go generating a runtime error similar to this:
+
+```bash
+sql: converting argument $1 type: uint64 values with high bit set are not supported.
+```
+
+By sticking with an int64 in our Go code, we eliminate the risk of ever encountering this error.
+
 ## Additional Information
 
 ### How different Go Types are encoded