diff --git a/src/main/java/io/asyncer/r2dbc/mysql/ConnectionContext.java b/src/main/java/io/asyncer/r2dbc/mysql/ConnectionContext.java
index 3039ea19b..a1735caa8 100644
--- a/src/main/java/io/asyncer/r2dbc/mysql/ConnectionContext.java
+++ b/src/main/java/io/asyncer/r2dbc/mysql/ConnectionContext.java
@@ -57,6 +57,7 @@ public final class ConnectionContext implements CodecContext {
      */
     private volatile short serverStatuses = ServerStatuses.AUTO_COMMIT;
 
+    @Nullable
     private volatile Capability capability = null;
 
     ConnectionContext(ZeroDateOption zeroDateOption, @Nullable Path localInfilePath,
@@ -109,7 +110,8 @@ public ZoneId getServerZoneId() {
 
     @Override
     public boolean isMariaDb() {
-        return capability.isMariaDb() || serverVersion.isMariaDb();
+        final Capability c = capability;
+        return c != null && (c.isMariaDb() || serverVersion.isMariaDb());
     }
 
     boolean shouldSetServerZoneId() {