diff --git a/rslib/src/storage/config/mod.rs b/rslib/src/storage/config/mod.rs
index 437888092..53e0ba8b5 100644
--- a/rslib/src/storage/config/mod.rs
+++ b/rslib/src/storage/config/mod.rs
@@ -16,10 +16,10 @@ impl SqliteStorage {
         usn: Usn,
         mtime: TimestampSecs,
     ) -> Result<()> {
-        let json = serde_json::to_string(val)?;
+        let json = serde_json::to_vec(val)?;
         self.db
             .prepare_cached(include_str!("add.sql"))?
-            .execute(params![key, usn, mtime, json])?;
+            .execute(params![key, usn, mtime, &json])?;
         Ok(())
     }
 
@@ -34,7 +34,8 @@ impl SqliteStorage {
         self.db
             .prepare_cached(include_str!("get.sql"))?
             .query_and_then(&[key], |row| {
-                serde_json::from_str(row.get_raw(0).as_str()?).map_err(Into::into)
+                let blob = row.get_raw(0).as_blob()?;
+                serde_json::from_slice(blob).map_err(Into::into)
             })?
             .next()
             .transpose()
@@ -44,7 +45,7 @@ impl SqliteStorage {
         self.db
             .prepare("select key, val from config")?
             .query_and_then(NO_PARAMS, |row| {
-                let val: Value = serde_json::from_str(row.get_raw(1).as_str()?)?;
+                let val: Value = serde_json::from_slice(row.get_raw(1).as_blob()?)?;
                 Ok((row.get::<usize, String>(0)?, val))
             })?
             .collect()
diff --git a/rslib/src/storage/deckconf/mod.rs b/rslib/src/storage/deckconf/mod.rs
index e1a20e963..096216bef 100644
--- a/rslib/src/storage/deckconf/mod.rs
+++ b/rslib/src/storage/deckconf/mod.rs
@@ -15,7 +15,7 @@ impl SqliteStorage {
         self.db
             .prepare_cached("select config from deck_config")?
             .query_and_then(NO_PARAMS, |row| -> Result<_> {
-                Ok(serde_json::from_str(row.get_raw(0).as_str()?)?)
+                Ok(serde_json::from_slice(row.get_raw(0).as_blob()?)?)
             })?
             .collect()
     }
@@ -24,7 +24,7 @@ impl SqliteStorage {
         self.db
             .prepare_cached(include_str!("get.sql"))?
             .query_and_then(params![dcid], |row| -> Result<_> {
-                Ok(serde_json::from_str(row.get_raw(0).as_str()?)?)
+                Ok(serde_json::from_slice(row.get_raw(0).as_blob()?)?)
             })?
             .next()
             .transpose()
@@ -38,7 +38,7 @@ impl SqliteStorage {
                 conf.name,
                 conf.mtime,
                 conf.usn,
-                &serde_json::to_string(conf)?,
+                &serde_json::to_vec(conf)?,
             ])?;
         let id = self.db.last_insert_rowid();
         if conf.id.0 != id {
@@ -57,7 +57,7 @@ impl SqliteStorage {
                 conf.name,
                 conf.mtime,
                 conf.usn,
-                &serde_json::to_string(conf)?,
+                &serde_json::to_vec(conf)?,
                 conf.id,
             ])?;
         Ok(())
diff --git a/rslib/src/storage/sqlite.rs b/rslib/src/storage/sqlite.rs
index 036a62d32..a7a7175ac 100644
--- a/rslib/src/storage/sqlite.rs
+++ b/rslib/src/storage/sqlite.rs
@@ -153,16 +153,21 @@ impl SqliteStorage {
     pub(crate) fn open_or_create(path: &Path, i18n: &I18n) -> Result<Self> {
         let db = open_or_create_collection_db(path)?;
         let (create, ver) = schema_version(&db)?;
-        if ver > SCHEMA_MAX_VERSION {
+
+        let err = match ver {
+            v if v < SCHEMA_MIN_VERSION => Some(DBErrorKind::FileTooOld),
+            v if v > SCHEMA_MAX_VERSION => Some(DBErrorKind::FileTooNew),
+            12 | 13 => {
+                // as schema definition changed, user must perform clean
+                // shutdown to return to schema 11 prior to running this version
+                Some(DBErrorKind::FileTooNew)
+            }
+            _ => None,
+        };
+        if let Some(kind) = err {
             return Err(AnkiError::DBError {
                 info: "".to_string(),
-                kind: DBErrorKind::FileTooNew,
-            });
-        }
-        if ver < SCHEMA_MIN_VERSION {
-            return Err(AnkiError::DBError {
-                info: "".to_string(),
-                kind: DBErrorKind::FileTooOld,
+                kind,
             });
         }
 
diff --git a/rslib/src/storage/upgrades/schema12_upgrade.sql b/rslib/src/storage/upgrades/schema12_upgrade.sql
index 54892fd73..8e80c34d4 100644
--- a/rslib/src/storage/upgrades/schema12_upgrade.sql
+++ b/rslib/src/storage/upgrades/schema12_upgrade.sql
@@ -3,7 +3,7 @@ create table deck_config (
   name text not null collate unicase,
   mtime_secs integer not null,
   usn integer not null,
-  config text not null
+  config blob not null
 );
 update col
 set
diff --git a/rslib/src/storage/upgrades/schema14_upgrade.sql b/rslib/src/storage/upgrades/schema14_upgrade.sql
index 128087d85..4893e8d3b 100644
--- a/rslib/src/storage/upgrades/schema14_upgrade.sql
+++ b/rslib/src/storage/upgrades/schema14_upgrade.sql
@@ -2,7 +2,7 @@ create table config (
   key text not null primary key,
   usn integer not null,
   mtime_secs integer not null,
-  val text not null
+  val blob not null
 ) without rowid;
 update col
 set