diff --git a/fastserde/avro-fastserde-tests-common/src/test/java/com/linkedin/avro/fastserde/file/FastSerdeWithDataFileStreamTest.java b/fastserde/avro-fastserde-tests-common/src/test/java/com/linkedin/avro/fastserde/file/FastSerdeWithDataFileStreamTest.java
index 4e38ef84..1e7b9711 100644
--- a/fastserde/avro-fastserde-tests-common/src/test/java/com/linkedin/avro/fastserde/file/FastSerdeWithDataFileStreamTest.java
+++ b/fastserde/avro-fastserde-tests-common/src/test/java/com/linkedin/avro/fastserde/file/FastSerdeWithDataFileStreamTest.java
@@ -53,7 +53,7 @@ void dataFileStreamShouldReadTheSameValuesAsValuesSentToDataFileWriter() throws
         DataFileStream<OuterRecord1> dataFileStream = new DataFileStream<>(inputStream, datumReader);
 
         // when: pre-populated bytes array is consumed by DataFileStream
-        for (OuterRecord1 outerRecord : dataFileStream) { // throws NPE
+        for (OuterRecord1 outerRecord : dataFileStream) {
             InnerRecord1 innerRecord = (InnerRecord1) FastSerdeTestsSupport.getField(outerRecord, "innerRecord");
             CharSequence comment = (CharSequence) FastSerdeTestsSupport.getField(innerRecord, "comment");
             actualComments.add(comment.toString());
diff --git a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastDeserializer.java b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastDeserializer.java
index fb6c579c..f7f4097c 100644
--- a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastDeserializer.java
+++ b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastDeserializer.java
@@ -2,6 +2,8 @@
 
 import com.linkedin.avro.fastserde.customized.DatumReaderCustomization;
 import java.io.IOException;
+
+import org.apache.avro.Schema;
 import org.apache.avro.io.Decoder;
 
 import static com.linkedin.avro.fastserde.customized.DatumReaderCustomization.*;
@@ -17,5 +19,15 @@ default T deserialize(T reuse, Decoder d) throws IOException {
     return deserialize(reuse, d, DEFAULT_DATUM_READER_CUSTOMIZATION);
   }
 
+  /**
+   * Set the writer's schema.
+   * @see org.apache.avro.io.DatumReader#setSchema(Schema)
+   */
+  default void setSchema(Schema writerSchema) {
+    // Implement this method only in vanilla-avro-based classes (e.g. fallback scenario).
+    // Normally for generated deserializers it doesn't make sense.
+    throw new UnsupportedOperationException("Can't change schema for already generated class.");
+  }
+
   T deserialize(T reuse, Decoder d, DatumReaderCustomization customization) throws IOException;
 }
diff --git a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastGenericDatumReader.java b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastGenericDatumReader.java
index fb0d663f..213d0776 100644
--- a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastGenericDatumReader.java
+++ b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastGenericDatumReader.java
@@ -87,6 +87,8 @@ public void setSchema(Schema schema) {
     if (readerSchema == null) {
       readerSchema = writerSchema;
     }
+
+    coldDeserializer.setSchema(schema);
   }
 
   @Override
diff --git a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeCache.java b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeCache.java
index 99204964..29503d54 100644
--- a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeCache.java
+++ b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeCache.java
@@ -183,7 +183,7 @@ public static boolean isSupportedForFastSerializer(Schema.Type schemaType) {
         Schema.Type.ARRAY);
   }
 
-  public static boolean isFastDeserializer(FastDeserializer deserializer) {
+  public static boolean isFastDeserializer(FastDeserializer<?> deserializer) {
     return deserializer.isBackedByGeneratedClass();
   }
 
@@ -476,7 +476,7 @@ private FastDeserializer<?> buildSpecificDeserializer(Schema writerSchema, Schem
       LOGGER.error("Deserializer class instantiation exception", e);
     }
 
-    return new FastSerdeUtils.FastDeserializerWithAvroSpecificImpl(writerSchema, readerSchema, modelData, customization, failFast, true);
+    return new FastSerdeUtils.FastDeserializerWithAvroSpecificImpl<>(writerSchema, readerSchema, modelData, customization, failFast, true);
   }
 
   /**
@@ -536,7 +536,7 @@ private FastDeserializer<?> buildGenericDeserializer(Schema writerSchema, Schema
       LOGGER.error("Deserializer class instantiation exception:", e);
     }
 
-    return new FastSerdeUtils.FastDeserializerWithAvroGenericImpl(writerSchema, readerSchema, modelData, customization, failFast, true);
+    return new FastSerdeUtils.FastDeserializerWithAvroGenericImpl<>(writerSchema, readerSchema, modelData, customization, failFast, true);
   }
 
   public FastSerializer<?> buildFastSpecificSerializer(Schema schema, SpecificData modelData) {
diff --git a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeUtils.java b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeUtils.java
index c9bc079f..333ac419 100644
--- a/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeUtils.java
+++ b/fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastSerdeUtils.java
@@ -52,6 +52,11 @@ public FastDeserializerWithAvroSpecificImpl(Schema writerSchema, Schema readerSc
       this.runtimeClassGenerationDone = runtimeClassGenerationDone;
     }
 
+    @Override
+    public void setSchema(Schema writerSchema) {
+      this.customizedDatumReader.setSchema(writerSchema);
+    }
+
     @Override
     public V deserialize(V reuse, Decoder d, DatumReaderCustomization customization) throws IOException {
       if (failFast) {
@@ -103,6 +108,11 @@ public FastDeserializerWithAvroGenericImpl(Schema writerSchema, Schema readerSch
       this.runtimeClassGenerationDone = runtimeClassGenerationDone;
     }
 
+    @Override
+    public void setSchema(Schema writerSchema) {
+      customizedDatumReader.setSchema(writerSchema);
+    }
+
     @Override
     public V deserialize(V reuse, Decoder d, DatumReaderCustomization customization) throws IOException {
       if (failFast) {