diff --git a/src/main/java/org/bricolages/mys3dump/Partition.java b/src/main/java/org/bricolages/mys3dump/Partition.java
index 4f65404..6024289 100644
--- a/src/main/java/org/bricolages/mys3dump/Partition.java
+++ b/src/main/java/org/bricolages/mys3dump/Partition.java
@@ -27,7 +27,7 @@ List<Partition> split(int n) {
             partitionSize = (long) Math.ceil(estRowCount / (double) n);
         }
         for (Long pStart = start, pEnd; pStart <= end; pStart = pEnd + 1) {
-            pEnd = pStart + partitionSize;
+            pEnd = pStart + partitionSize - 1;
             if (pEnd >= end) pEnd = end;
             pts.add(new Partition(columnName, pStart, pEnd));
         }
diff --git a/src/test/java/org/bricolages/mys3dump/PartitionTest.java b/src/test/java/org/bricolages/mys3dump/PartitionTest.java
new file mode 100644
index 0000000..9041633
--- /dev/null
+++ b/src/test/java/org/bricolages/mys3dump/PartitionTest.java
@@ -0,0 +1,32 @@
+package org.bricolages.mys3dump;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+class PartitionTest {
+    @Test
+    void splitIntoPartitions() {
+        // Split 20 rows (estimated) into 5 partitions
+        List<Partition> partitions = new Partition("id", Long.valueOf(1), Long.valueOf(20)).split(5);
+        assertEquals(5, partitions.size());
+        assertEquals("id BETWEEN 1 AND 4", partitions.get(0).toString());
+        assertEquals("id BETWEEN 5 AND 8", partitions.get(1).toString());
+        assertEquals("id BETWEEN 9 AND 12", partitions.get(2).toString());
+        assertEquals("id BETWEEN 13 AND 16", partitions.get(3).toString());
+        assertEquals("id BETWEEN 17 AND 20", partitions.get(4).toString());
+    }
+
+    @Test
+    void splitIntoPartitionsWithRemainder() {
+        // Split 21 rows (estimated) into 5 partitions
+        List<Partition> partitions = new Partition("id", Long.valueOf(1), Long.valueOf(21)).split(5);
+        assertEquals(5, partitions.size());
+        assertEquals("id BETWEEN 1 AND 5", partitions.get(0).toString());
+        assertEquals("id BETWEEN 6 AND 10", partitions.get(1).toString());
+        assertEquals("id BETWEEN 11 AND 15", partitions.get(2).toString());
+        assertEquals("id BETWEEN 16 AND 20", partitions.get(3).toString());
+        assertEquals("id BETWEEN 20 AND 21", partitions.get(4).toString());
+    }
+}