1 files changed, 2 insertions, 0 deletions
diff --git a/UPGRADING b/UPGRADING
index 9318b711..913da8d4 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -15,6 +15,8 @@ ALTER TABLE Users ADD COLUMN PGPKey VARCHAR(40) NULL DEFAULT NULL;
 
 3. Update Archive_Tar to version greater than 1.3.7.
 
+4. Enable the PDO MySQL extension (pdo_mysql.so) in "php.ini".
+
 From 1.9.0 to 1.9.1
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