diff --git a/lucene/core/src/java/org/apache/lucene/search/IndexSearcher.java b/lucene/core/src/java/org/apache/lucene/search/IndexSearcher.java
index 39c88ed6759..a165dfd9340 100644
--- a/lucene/core/src/java/org/apache/lucene/search/IndexSearcher.java
+++ b/lucene/core/src/java/org/apache/lucene/search/IndexSearcher.java
@@ -75,8 +75,8 @@ import org.apache.lucene.util.ThreadInterruptedException;
 public class IndexSearcher {
 
   // 32MB and at most 10,000 queries
-  private static final QueryCache DEFAULT_QUERY_CACHE = new LRUQueryCache(10000, 1 << 25);
-  private static final QueryCachingPolicy DEFAULT_CACHING_POLICY = new UsageTrackingQueryCachingPolicy();
+  private static QueryCache DEFAULT_QUERY_CACHE = new LRUQueryCache(10000, 1 << 25);
+  private static QueryCachingPolicy DEFAULT_CACHING_POLICY = new UsageTrackingQueryCachingPolicy();
 
   final IndexReader reader; // package private for testing!
   
@@ -106,7 +106,23 @@ public class IndexSearcher {
   public static Similarity getDefaultSimilarity() {
     return defaultSimilarity;
   }
-  
+
+  /**
+   * Expert: set the default {@link QueryCache} instance.
+   * @lucene.internal
+   */
+  public static void setDefaultQueryCache(QueryCache defaultQueryCache) {
+    DEFAULT_QUERY_CACHE = defaultQueryCache;
+  }
+
+  /**
+   * Expert: set the default {@link QueryCachingPolicy} instance.
+   * @lucene.internal
+   */
+  public static void setDefaultQueryCachingPolicy(QueryCachingPolicy defaultQueryCachingPolicy) {
+    DEFAULT_CACHING_POLICY = defaultQueryCachingPolicy;
+  }
+
   /** The Similarity implementation used by this searcher. */
   private Similarity similarity = defaultSimilarity;
 
diff --git a/lucene/core/src/test/org/apache/lucene/search/TestBooleanQuery.java b/lucene/core/src/test/org/apache/lucene/search/TestBooleanQuery.java
index 75d4cc69c96..a226a99bed6 100644
--- a/lucene/core/src/test/org/apache/lucene/search/TestBooleanQuery.java
+++ b/lucene/core/src/test/org/apache/lucene/search/TestBooleanQuery.java
@@ -602,7 +602,8 @@ public class TestBooleanQuery extends LuceneTestCase {
     w.commit();
 
     DirectoryReader reader = w.getReader();
-    final IndexSearcher searcher = new IndexSearcher(reader);
+    final IndexSearcher searcher = newSearcher(reader);
+    searcher.setQueryCache(null); // to still have approximations
 
     PhraseQuery pq = new PhraseQuery();
     pq.add(new Term("field", "a"));
@@ -633,6 +634,7 @@ public class TestBooleanQuery extends LuceneTestCase {
 
     DirectoryReader reader = w.getReader();
     final IndexSearcher searcher = new IndexSearcher(reader);
+    searcher.setQueryCache(null); // to still have approximations
 
     PhraseQuery pq = new PhraseQuery();
     pq.add(new Term("field", "a"));
@@ -662,7 +664,8 @@ public class TestBooleanQuery extends LuceneTestCase {
     w.commit();
 
     DirectoryReader reader = w.getReader();
-    final IndexSearcher searcher = new IndexSearcher(reader);
+    final IndexSearcher searcher = newSearcher(reader);
+    searcher.setQueryCache(null); // to still have approximations
 
     PhraseQuery pq = new PhraseQuery();
     pq.add(new Term("field", "a"));
@@ -693,6 +696,7 @@ public class TestBooleanQuery extends LuceneTestCase {
 
     DirectoryReader reader = w.getReader();
     final IndexSearcher searcher = new IndexSearcher(reader);
+    searcher.setQueryCache(null); // to still have approximations
 
     PhraseQuery pq = new PhraseQuery();
     pq.add(new Term("field", "a"));
@@ -723,6 +727,7 @@ public class TestBooleanQuery extends LuceneTestCase {
 
     DirectoryReader reader = w.getReader();
     final IndexSearcher searcher = new IndexSearcher(reader);
+    searcher.setQueryCache(null); // to still have approximations
 
     PhraseQuery pq = new PhraseQuery();
     pq.add(new Term("field", "a"));
diff --git a/lucene/core/src/test/org/apache/lucene/search/TestConstantScoreQuery.java b/lucene/core/src/test/org/apache/lucene/search/TestConstantScoreQuery.java
index 5bea31c5f86..1142d9bf629 100644
--- a/lucene/core/src/test/org/apache/lucene/search/TestConstantScoreQuery.java
+++ b/lucene/core/src/test/org/apache/lucene/search/TestConstantScoreQuery.java
@@ -214,7 +214,8 @@ public class TestConstantScoreQuery extends LuceneTestCase {
     w.commit();
 
     DirectoryReader reader = w.getReader();
-    final IndexSearcher searcher = new IndexSearcher(reader);
+    final IndexSearcher searcher = newSearcher(reader);
+    searcher.setQueryCache(null); // to still have approximations
 
     PhraseQuery pq = new PhraseQuery();
     pq.add(new Term("field", "a"));
diff --git a/lucene/core/src/test/org/apache/lucene/search/TestQueryWrapperFilter.java b/lucene/core/src/test/org/apache/lucene/search/TestQueryWrapperFilter.java
index 6af1f607393..76b4def1fcb 100644
--- a/lucene/core/src/test/org/apache/lucene/search/TestQueryWrapperFilter.java
+++ b/lucene/core/src/test/org/apache/lucene/search/TestQueryWrapperFilter.java
@@ -203,6 +203,7 @@ public class TestQueryWrapperFilter extends LuceneTestCase {
     final IndexReader reader = writer.getReader();
     writer.close();
     final IndexSearcher searcher = new IndexSearcher(reader);
+    searcher.setQueryCache(null); // to still have approximations
     final Query query = new QueryWrapperFilter(new RandomApproximationQuery(new TermQuery(new Term("foo", "bar")), random()));
     final Weight weight = searcher.createNormalizedWeight(query, random().nextBoolean());
     final Scorer scorer = weight.scorer(reader.leaves().get(0), null);
diff --git a/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java b/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java
index 7c931e9431d..2464c5f01eb 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java
@@ -95,6 +95,7 @@ import org.apache.lucene.index.IndexReader.ReaderClosedListener;
 import org.apache.lucene.index.TermsEnum.SeekStatus;
 import org.apache.lucene.search.AssertingIndexSearcher;
 import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.search.LRUQueryCache;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.QueryCachingPolicy;
 import org.apache.lucene.search.IndexSearcher;
@@ -1649,6 +1650,12 @@ public abstract class LuceneTestCase extends Assert {
     }
   }
 
+  @Before
+  public void resetDefaultQueryCache() {
+    IndexSearcher.setDefaultQueryCache(new LRUQueryCache(10000, 1 << 25));
+    IndexSearcher.setDefaultQueryCachingPolicy(MAYBE_CACHE_POLICY);
+  }
+
   /**
    * Create a new searcher over the reader. This searcher might randomly use
    * threads.
@@ -1700,7 +1707,6 @@ public abstract class LuceneTestCase extends Assert {
         ret = random.nextBoolean() ? new IndexSearcher(r) : new IndexSearcher(r.getContext());
       }
       ret.setSimilarity(classEnvRule.similarity);
-      ret.setQueryCachingPolicy(MAYBE_CACHE_POLICY);
       return ret;
     } else {
       int threads = 0;