diff --git a/spark/src/main/scala/org/apache/spark/sql/delta/sources/DeltaSQLConf.scala b/spark/src/main/scala/org/apache/spark/sql/delta/sources/DeltaSQLConf.scala
index aa46bd9bd0..9d57ba2c00 100644
--- a/spark/src/main/scala/org/apache/spark/sql/delta/sources/DeltaSQLConf.scala
+++ b/spark/src/main/scala/org/apache/spark/sql/delta/sources/DeltaSQLConf.scala
@@ -1561,7 +1561,9 @@ trait DeltaSQLConfBase {
           |The casting behavior is governed by 'spark.sql.storeAssignmentPolicy'.
           |""".stripMargin)
       .booleanConf
-      .createWithDefault(true)
+      // This feature doesn't properly support structs with missing fields and is disabled until a
+      // fix is implemented.
+      .createWithDefault(false)
 
   val DELTA_CDF_UNSAFE_BATCH_READ_ON_INCOMPATIBLE_SCHEMA_CHANGES =
     buildConf("changeDataFeed.unsafeBatchReadOnIncompatibleSchemaChanges.enabled")
diff --git a/spark/src/test/scala/org/apache/spark/sql/delta/DeltaInsertIntoImplicitCastSuite.scala b/spark/src/test/scala/org/apache/spark/sql/delta/DeltaInsertIntoImplicitCastSuite.scala
index e6e965e0b8..c014feb228 100644
--- a/spark/src/test/scala/org/apache/spark/sql/delta/DeltaInsertIntoImplicitCastSuite.scala
+++ b/spark/src/test/scala/org/apache/spark/sql/delta/DeltaInsertIntoImplicitCastSuite.scala
@@ -17,8 +17,8 @@
 package org.apache.spark.sql.delta
 
 import org.apache.spark.sql.delta.sources.DeltaSQLConf
-
 import org.apache.spark.sql.SaveMode
+import org.apache.spark.sql.internal.SQLConf
 import org.apache.spark.sql.types._
 
 /**
@@ -32,6 +32,12 @@ import org.apache.spark.sql.types._
  */
 class DeltaInsertIntoImplicitCastSuite extends DeltaInsertIntoTest {
 
+  override def beforeAll(): Unit = {
+    super.beforeAll()
+    spark.conf.set(DeltaSQLConf.DELTA_STREAMING_SINK_ALLOW_IMPLICIT_CASTS.key, "true")
+    spark.conf.set(SQLConf.ANSI_ENABLED.key, "true")
+  }
+
   for (schemaEvolution <- BOOLEAN_DOMAIN) {
     testInserts("insert with implicit up and down cast on top-level fields, " +
       s"schemaEvolution=$schemaEvolution")(