diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index a061ba4..e64bf8b 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -1,5 +1,6 @@
 parameters:
-    phpVersion: 80300
+    phpVersion: 80100
     level: 3
     paths:
         - src
+        - tests
diff --git a/src/Bridge/AbstractBridge.php b/src/Bridge/AbstractBridge.php
index c02edcc..335950f 100644
--- a/src/Bridge/AbstractBridge.php
+++ b/src/Bridge/AbstractBridge.php
@@ -48,6 +48,7 @@ abstract class AbstractBridge extends DefaultQueryBuilder implements Bridge
     private ?string $serverVersion = null;
     private bool $serverVersionLookedUp = false;
     private ?string $vendorName = null;
+    private ?string $vendorVersion = null;
     private ?Transaction $currentTransaction = null;
     private ?ErrorConverter $errorConverter = null;
     private ?SchemaManager $schemaManager = null;
@@ -97,6 +98,14 @@ public function setServerInfo(?string $serverName = null, ?string $serverVersion
         $this->serverVersionLookedUp = (null !== ($this->serverVersion = $serverVersion));
     }
 
+    /**
+     * Please override.
+     */
+    protected function lookupServerName(): ?string
+    {
+        return null;
+    }
+
     #[\Override]
     public function getServerName(): ?string
     {
@@ -104,49 +113,35 @@ public function getServerName(): ?string
             return $this->serverName;
         }
 
-        $this->serverName = $this->lookupServerName();
         $this->serverNameLookedUp = true;
 
-        return $this->serverName;
+        return $this->serverName = $this->lookupServerName();
     }
 
     /**
-     * Get error converter.
+     * Please override.
      */
-    protected function getErrorConverter(): ErrorConverter
+    protected function lookupServerVersion(): ?string
     {
-        return $this->errorConverter ??= $this->createErrorConverter();
+        return null;
     }
 
-    /**
-     * @internal
-     *    For dependency injection only.
-     */
-    public function setErrorConverter(ErrorConverter $errorConverter): void
+    #[\Override]
+    public function getServerVersion(): ?string
     {
-        $this->errorConverter = $errorConverter;
-    }
+        if ($this->serverVersionLookedUp) {
+            return $this->serverVersion;
+        }
 
-    /**
-     * Please override.
-     */
-    protected function createErrorConverter(): ErrorConverter
-    {
-        return new PassthroughErrorConverter();
-    }
+        $this->serverVersionLookedUp = true;
 
-    /**
-     * Please override.
-     */
-    protected function lookupServerName(): ?string
-    {
-        return null;
+        return $this->serverVersion = $this->lookupServerVersion();
     }
 
     #[\Override]
     public function getVendorName(): string
     {
-        if ($this->vendorName) {
+        if (null !== $this->vendorName) {
             return $this->vendorName;
         }
 
@@ -180,12 +175,11 @@ public function getVendorName(): string
     #[\Override]
     public function getVendorVersion(): string
     {
-        if ($this->serverVersionLookedUp && $this->serverVersion) {
-            return $this->serverVersion;
+        if (null !== $this->vendorVersion) {
+            return $this->vendorVersion;
         }
-        $this->serverVersionLookedUp = true;
 
-        $serverVersion = $this->lookupServerVersion();
+        $serverVersion = $this->getServerVersion();
 
         $matches = [];
         if ($serverVersion && \preg_match('/(\d+\.|)\d+\.\d+/ims', $serverVersion, $matches)) {
@@ -225,13 +219,6 @@ public function getServerFlavor(): ?string
         return Vendor::UNKNOWN !== ($value = $this->getVendorName()) ? $value : null;
     }
 
-    /** @deprecated */
-    #[\Override]
-    public function getServerVersion(): ?string
-    {
-        return '0.0.0' !== ($value = $this->getVendorVersion()) ? $value : null;
-    }
-
     /** @deprecated */
     #[\Override]
     public function isVersionLessThan(string $version): bool
@@ -249,19 +236,13 @@ public function isVersionGreaterOrEqualThan(string $version): bool
     #[\Override]
     public function getCurrentDatabase(): string
     {
-        if (null === $this->currentDatabase) {
-            $this->currentDatabase = (string) $this->raw('SELECT ?', [new CurrentDatabase()])->executeQuery()->fetchOne();
-        }
-        return $this->currentDatabase;
+        return $this->currentDatabase ??= (string) $this->raw('SELECT ?', [new CurrentDatabase()])->executeQuery()->fetchOne();
     }
 
     #[\Override]
     public function getDefaultSchema(): string
     {
-        if (null === $this->currentSchema) {
-            $this->currentSchema = (string) $this->raw('SELECT ?', [new CurrentSchema()])->executeQuery()->fetchOne();
-        }
-        return $this->currentSchema;
+        return $this->currentSchema ??= (string) $this->raw('SELECT ?', [new CurrentSchema()])->executeQuery()->fetchOne();
     }
 
     /**
@@ -370,12 +351,29 @@ public function beginTransaction(int $isolationLevel = Transaction::REPEATABLE_R
         return $this->createTransaction($isolationLevel, $allowPending)->start();
     }
 
+    /**
+     * Get error converter.
+     */
+    protected function getErrorConverter(): ErrorConverter
+    {
+        return $this->errorConverter ??= $this->createErrorConverter();
+    }
+
+    /**
+     * @internal
+     *    For dependency injection only.
+     */
+    public function setErrorConverter(ErrorConverter $errorConverter): void
+    {
+        $this->errorConverter = $errorConverter;
+    }
+
     /**
      * Please override.
      */
-    protected function lookupServerVersion(): ?string
+    protected function createErrorConverter(): ErrorConverter
     {
-        return null;
+        return new PassthroughErrorConverter();
     }
 
     /**
diff --git a/src/Bridge/Bridge.php b/src/Bridge/Bridge.php
index a71cfe4..4c74d9f 100644
--- a/src/Bridge/Bridge.php
+++ b/src/Bridge/Bridge.php
@@ -16,25 +16,22 @@ interface Bridge extends DatabaseSession
     public function disableErrorConverter(): void;
 
     /**
-     * Get server name.
+     * Get server name as exposed by the server itself, not normalized.
      */
     public function getServerName(): ?string;
 
     /**
-     * Get server product type.
-     *
-     * @deprecated
-     * @see DatabaseSession::getVendorName()
+     * Get server version as exposed by the server itself, not normalized.
      */
-    public function getServerFlavor(): ?string;
+    public function getServerVersion(): ?string;
 
     /**
-     * Get server version.
+     * Get normalized vendor name.
      *
      * @deprecated
-     * @see DatabaseSession::getVendorVersion()
+     * @see DatabaseSession::getVendorName()
      */
-    public function getServerVersion(): ?string;
+    public function getServerFlavor(): ?string;
 
     /**
      * Version is less than given.
diff --git a/src/Bridge/Doctrine/DoctrineQueryBuilder.php b/src/Bridge/Doctrine/DoctrineQueryBuilder.php
index 8bf52ea..9cc2f55 100644
--- a/src/Bridge/Doctrine/DoctrineQueryBuilder.php
+++ b/src/Bridge/Doctrine/DoctrineQueryBuilder.php
@@ -83,7 +83,7 @@ protected function lookupServerVersion(): ?string
             return $this->doctrineServerVersion = $this->connection->getServerVersion();
         }
 
-        return $this->doctrineServerVersion = 'unknown';
+        return $this->doctrineServerVersion = '0.0.0';
     }
 
     #[\Override]
@@ -98,6 +98,7 @@ protected function createEscaper(): Escaper
         };
     }
 
+    #[\Override]
     protected function createWriter(Escaper $escaper, Converter $converter): Writer
     {
         // @todo Temporary deactivated, needs a way to add converter
diff --git a/src/Vendor.php b/src/Vendor.php
index 674bd23..018bef4 100644
--- a/src/Vendor.php
+++ b/src/Vendor.php
@@ -4,6 +4,8 @@
 
 namespace MakinaCorpus\QueryBuilder;
 
+use MakinaCorpus\QueryBuilder\Error\QueryBuilderError;
+
 /**
  * RDMBS identification.
  *
@@ -30,7 +32,7 @@ public static function versionNormalize(string $version): string
         if (\preg_match('/(\d+)(\.\d+|)(\.\d+|).*/ims', $version, $matches)) {
             return $matches[1] . ($matches[2] ?: '.0') . ($matches[3] ?: '.0');
         }
-        throw new \Exception(\sprintf("Version '%s', is not in 'x.y.z' semantic format", $version));
+        throw new QueryBuilderError(\sprintf("Version '%s', is not in 'x.y.z' semantic format", $version));
     }
 
     /**
@@ -47,7 +49,7 @@ public static function versionCompare(string $userGiven, string $serverVersion,
             '=' => 0 === \version_compare($userGiven, $serverVersion),
             '>=' => 0 <= \version_compare($userGiven, $serverVersion),
             '>' => 0 < \version_compare($userGiven, $serverVersion),
-            default => throw new \Exception("Version comparison operator must be one of '<', '<=', '=', '>=', '>'"),
+            default => throw new QueryBuilderError("Version comparison operator must be one of '<', '<=', '=', '>=', '>'"),
         };
     }