diff --git a/paimon-common/src/main/java/org/apache/paimon/fileindex/rangebitmap/RangeBitmapFileIndex.java b/paimon-common/src/main/java/org/apache/paimon/fileindex/rangebitmap/RangeBitmapFileIndex.java
index 8b3ef92f22eb..0cfa5fa56fbf 100644
--- a/paimon-common/src/main/java/org/apache/paimon/fileindex/rangebitmap/RangeBitmapFileIndex.java
+++ b/paimon-common/src/main/java/org/apache/paimon/fileindex/rangebitmap/RangeBitmapFileIndex.java
@@ -72,9 +72,18 @@ private static class Writer extends FileIndexWriter {
         public Writer(DataType dataType, Options options) {
             KeyFactory factory = KeyFactory.create(dataType);
             String chunkSize = options.getString(CHUNK_SIZE, factory.defaultChunkSize());
+            long bytes = MemorySize.parse(chunkSize).getBytes();
+            // the chunk size becomes an eagerly allocated per-chunk buffer, so it has to fit an
+            // int. Narrowing it silently substitutes a different size: "2g" becomes negative and
+            // fails only once the writer allocates, "4g" becomes 0 and "5g" becomes 1g.
+            if (bytes > Integer.MAX_VALUE) {
+                throw new IllegalArgumentException(
+                        String.format(
+                                "The '%s' option must not exceed 2147483647 bytes, but was '%s'.",
+                                CHUNK_SIZE, chunkSize));
+            }
             this.converter = factory.createConverter();
-            this.appender =
-                    new RangeBitmap.Appender(factory, (int) MemorySize.parse(chunkSize).getBytes());
+            this.appender = new RangeBitmap.Appender(factory, (int) bytes);
         }
 
         @Override
diff --git a/paimon-common/src/test/java/org/apache/paimon/fileindex/rangebitmap/RangeBitmapFileIndexTest.java b/paimon-common/src/test/java/org/apache/paimon/fileindex/rangebitmap/RangeBitmapFileIndexTest.java
index 8e94eba87317..5edac83812e3 100644
--- a/paimon-common/src/test/java/org/apache/paimon/fileindex/rangebitmap/RangeBitmapFileIndexTest.java
+++ b/paimon-common/src/test/java/org/apache/paimon/fileindex/rangebitmap/RangeBitmapFileIndexTest.java
@@ -50,6 +50,7 @@
 import static org.apache.paimon.predicate.SortValue.SortDirection.ASCENDING;
 import static org.apache.paimon.predicate.SortValue.SortDirection.DESCENDING;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 /** test for {@link RangeBitmapFileIndex}. */
 public class RangeBitmapFileIndexTest {
@@ -57,6 +58,34 @@ public class RangeBitmapFileIndexTest {
     private static final int ROW_COUNT = 10000;
     private static final int BOUND = 1000000;
 
+    @Test
+    public void testChunkSizeBeyondIntRangeRejected() {
+        VarCharType varCharType = new VarCharType();
+
+        // the boundary is the whole guard: one byte past int range is rejected, int range itself
+        // is accepted. "2g" and "4g" would both only re-test the same comparison
+        Options justPastIntRange = new Options();
+        justPastIntRange.setString(RangeBitmapFileIndex.CHUNK_SIZE, "2147483648 bytes");
+        assertThatThrownBy(
+                        () ->
+                                new RangeBitmapFileIndex(varCharType, justPastIntRange)
+                                        .createWriter())
+                .isInstanceOf(IllegalArgumentException.class)
+                .hasMessageContaining("chunk-size");
+
+        Options atIntRange = new Options();
+        atIntRange.setString(RangeBitmapFileIndex.CHUNK_SIZE, "2147483647 bytes");
+        assertThat(new RangeBitmapFileIndex(varCharType, atIntRange).createWriter()).isNotNull();
+
+        // a large but in-range chunk size still writes and serializes
+        Options valid = new Options();
+        valid.setString(RangeBitmapFileIndex.CHUNK_SIZE, "16mb");
+        FileIndexWriter writer = new RangeBitmapFileIndex(varCharType, valid).createWriter();
+        writer.write(BinaryString.fromString("a"));
+        writer.write(BinaryString.fromString("b"));
+        assertThat(writer.serializedBytes()).isNotEmpty();
+    }
+
     @RepeatedTest(10)
     public void test() {
         String prefix = "hello-";