diff --git a/client/src/main/java/com/metamx/druid/query/filter/SelectorDimFilter.java b/client/src/main/java/com/metamx/druid/query/filter/SelectorDimFilter.java
index 039d9893411..dd2f39dfe13 100644
--- a/client/src/main/java/com/metamx/druid/query/filter/SelectorDimFilter.java
+++ b/client/src/main/java/com/metamx/druid/query/filter/SelectorDimFilter.java
@@ -39,7 +39,7 @@ public class SelectorDimFilter implements DimFilter
   )
   {
     Preconditions.checkArgument(dimension != null, "dimension must not be null");
-    Preconditions.checkArgument(value != null, "value must not be null");
+
     this.dimension = dimension;
     this.value = value;
   }
@@ -48,7 +48,7 @@ public class SelectorDimFilter implements DimFilter
   public byte[] getCacheKey()
   {
     byte[] dimensionBytes = dimension.getBytes();
-    byte[] valueBytes = value.getBytes();
+    byte[] valueBytes = (value == null) ? new byte[]{} : value.getBytes();
 
     return ByteBuffer.allocate(1 + dimensionBytes.length + valueBytes.length)
                      .put(DimFilterCacheHelper.SELECTOR_CACHE_ID)