diff --git a/presto-main/src/main/java/com/facebook/presto/sql/planner/RelationPlan.java b/presto-main/src/main/java/com/facebook/presto/sql/planner/RelationPlan.java
index <HASH>..<HASH> 100644
--- a/presto-main/src/main/java/com/facebook/presto/sql/planner/RelationPlan.java
+++ b/presto-main/src/main/java/com/facebook/presto/sql/planner/RelationPlan.java
@@ -60,7 +60,7 @@ class RelationPlan
 
     public Symbol getSymbol(int fieldIndex)
     {
-        checkArgument(fieldIndex >= 0 && fieldIndex < fieldMappings.size() && fieldMappings.get(fieldIndex) != null, "No field->symbol mapping for field %s", fieldIndex);
+        checkArgument(fieldIndex >= 0 && fieldIndex < fieldMappings.size(), "No field->symbol mapping for field %s", fieldIndex);
         return fieldMappings.get(fieldIndex);
     }
Remove redundant null check

`fieldMappings` is a `ImmutableList`, it cannot contain nulls.