diff --git a/core/src/main/java/de/bwaldvogel/mongo/backend/AbstractMongoDatabase.java b/core/src/main/java/de/bwaldvogel/mongo/backend/AbstractMongoDatabase.java
index 5d91a64d..5c530a60 100644
--- a/core/src/main/java/de/bwaldvogel/mongo/backend/AbstractMongoDatabase.java
+++ b/core/src/main/java/de/bwaldvogel/mongo/backend/AbstractMongoDatabase.java
@@ -427,25 +427,34 @@ private void dropIndexes(MongoCollection<P> collection, Document query) {
         Object index = query.get("index");
         Assert.notNull(index, () -> "Index name must not be null");
         MongoCollection<P> indexCollection = indexes.get();
+        Document nsQuery = new Document("ns", collection.getFullName());
         if (Objects.equals(index, "*")) {
-            for (Document indexDocument : indexCollection.queryAll()) {
+            for (Document indexDocument : indexCollection.handleQuery(nsQuery)) {
                 Document indexKeys = (Document) indexDocument.get("key");
                 if (!isPrimaryKeyIndex(indexKeys)) {
                     dropIndex(collection, indexDocument);
                 }
             }
-        } else if (index instanceof String) {
-            dropIndex(collection, new Document("name", index));
         } else {
-            Document indexKeys = (Document) index;
-            Document indexQuery = new Document("key", indexKeys).append("ns", collection.getFullName());
-            Document indexToDrop = CollectionUtils.getSingleElement(indexCollection.handleQuery(indexQuery),
-                () -> new IndexNotFoundException(indexKeys));
+            if (index instanceof String indexName) {
+                nsQuery.append("name", indexName);
+            } else {
+                nsQuery.append("key", (Document) index);
+            }
+            Document indexToDrop = CollectionUtils.getSingleElement(indexCollection.handleQuery(nsQuery),
+                () -> createIndexNotFoundException(index));
             int numDeleted = dropIndex(collection, indexToDrop);
             Assert.equals(numDeleted, 1, () -> "Expected one deleted document");
         }
     }
 
+    private static IndexNotFoundException createIndexNotFoundException(Object index) {
+        if (index instanceof String indexName) {
+            return new IndexNotFoundException("index not found with name [" + indexName + "]");
+        }
+        return new IndexNotFoundException((Document) index);
+    }
+
     private int dropIndex(MongoCollection<P> collection, Document indexDescription) {
         String indexName = (String) indexDescription.get("name");
         dropIndex(collection, indexName);
diff --git a/test-common/src/main/java/de/bwaldvogel/mongo/backend/AbstractBackendTest.java b/test-common/src/main/java/de/bwaldvogel/mongo/backend/AbstractBackendTest.java
index 3bd4c9eb..eaa968b4 100755
--- a/test-common/src/main/java/de/bwaldvogel/mongo/backend/AbstractBackendTest.java
+++ b/test-common/src/main/java/de/bwaldvogel/mongo/backend/AbstractBackendTest.java
@@ -723,6 +723,82 @@ void testDropIndexes_twoIndexesWithTheSameKey() {
             );
     }
 
+    // https://github.com/bwaldvogel/mongo-java-server/issues/246
+    @Test
+    void testDropIndexes_string_twoIndexesWithTheSameKey() {
+        collection.insertOne(json("_id: 1, c: 10"));
+
+        MongoCollection<Document> otherCollection = getCollection("other");
+        otherCollection.insertOne(json("_id: 1, c: 10"));
+
+        String indexName = collection.createIndex(new Document("c", 1));
+        otherCollection.createIndex(new Document("c", 1));
+
+        assertThat(collection.listIndexes())
+            .containsExactlyInAnyOrder(
+                json("key: {_id: 1}").append("name", "_id_").append("v", 2),
+                json("key: {c: 1}").append("name", "c_1").append("v", 2)
+            );
+
+        assertThat(otherCollection.listIndexes())
+            .containsExactlyInAnyOrder(
+                json("key: {_id: 1}").append("name", "_id_").append("v", 2),
+                json("key: {c: 1}").append("name", "c_1").append("v", 2)
+            );
+
+        collection.dropIndex(indexName);
+
+        assertThat(collection.listIndexes())
+            .containsExactlyInAnyOrder(
+                json("key: {_id: 1}").append("name", "_id_").append("v", 2)
+            );
+
+        assertThat(otherCollection.listIndexes())
+            .containsExactlyInAnyOrder(
+                json("key: {_id: 1}").append("name", "_id_").append("v", 2),
+                json("key: {c: 1}").append("name", "c_1").append("v", 2)
+            );
+    }
+
+    // https://github.com/bwaldvogel/mongo-java-server/issues/247
+    @Test
+    void testDropIndexes_all() {
+        collection.insertOne(json("_id: 1, c: 10, d:1"));
+
+        MongoCollection<Document> otherCollection = getCollection("other");
+        otherCollection.insertOne(json("_id: 1, c: 10"));
+
+        collection.createIndex(new Document("c", 1));
+        collection.createIndex(new Document("d", 1));
+        otherCollection.createIndex(new Document("c", 1));
+
+        assertThat(collection.listIndexes())
+            .containsExactlyInAnyOrder(
+                json("key: {_id: 1}").append("name", "_id_").append("v", 2),
+                json("key: {c: 1}").append("name", "c_1").append("v", 2),
+                json("key: {d: 1}").append("name", "d_1").append("v", 2)
+            );
+
+        assertThat(otherCollection.listIndexes())
+            .containsExactlyInAnyOrder(
+                json("key: {_id: 1}").append("name", "_id_").append("v", 2),
+                json("key: {c: 1}").append("name", "c_1").append("v", 2)
+            );
+
+        collection.dropIndex("*");
+
+        assertThat(collection.listIndexes())
+            .containsExactlyInAnyOrder(
+                json("key: {_id: 1}").append("name", "_id_").append("v", 2)
+            );
+
+        assertThat(otherCollection.listIndexes())
+            .containsExactlyInAnyOrder(
+                json("key: {_id: 1}").append("name", "_id_").append("v", 2),
+                json("key: {c: 1}").append("name", "c_1").append("v", 2)
+            );
+    }
+
     @Test
     public void testCurrentOperations() {
         Document currentOperations = getAdminDb().getCollection("$cmd.sys.inprog").find().first();