diff --git a/core/src/main/java/org/elasticsearch/index/mapper/MappedFieldType.java b/core/src/main/java/org/elasticsearch/index/mapper/MappedFieldType.java
index 4c544dbf37c..fff041090a8 100644
--- a/core/src/main/java/org/elasticsearch/index/mapper/MappedFieldType.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/MappedFieldType.java
@@ -460,7 +460,7 @@ public abstract class MappedFieldType extends FieldType {
         return new FuzzyQuery(createTerm(value), fuzziness.asDistance(BytesRefs.toString(value)), prefixLength, maxExpansions, transpositions);
     }
 
-    public Query prefixQuery(Object value, @Nullable MultiTermQuery.RewriteMethod method, @Nullable QueryParseContext context) {
+    public Query prefixQuery(String value, @Nullable MultiTermQuery.RewriteMethod method, @Nullable QueryParseContext context) {
         PrefixQuery query = new PrefixQuery(createTerm(value));
         if (method != null) {
             query.setRewriteMethod(method);
diff --git a/core/src/main/java/org/elasticsearch/index/mapper/internal/IdFieldMapper.java b/core/src/main/java/org/elasticsearch/index/mapper/internal/IdFieldMapper.java
index 3e5a5092228..63fa41faea1 100644
--- a/core/src/main/java/org/elasticsearch/index/mapper/internal/IdFieldMapper.java
+++ b/core/src/main/java/org/elasticsearch/index/mapper/internal/IdFieldMapper.java
@@ -184,7 +184,7 @@ public class IdFieldMapper extends MetadataFieldMapper {
         }
 
         @Override
-        public Query prefixQuery(Object value, @Nullable MultiTermQuery.RewriteMethod method, @Nullable QueryParseContext context) {
+        public Query prefixQuery(String value, @Nullable MultiTermQuery.RewriteMethod method, @Nullable QueryParseContext context) {
             if (indexOptions() != IndexOptions.NONE || context == null) {
                 return super.prefixQuery(value, method, context);
             }
diff --git a/core/src/main/java/org/elasticsearch/index/query/PrefixQueryParser.java b/core/src/main/java/org/elasticsearch/index/query/PrefixQueryParser.java
index 078e597bcab..56387d90751 100644
--- a/core/src/main/java/org/elasticsearch/index/query/PrefixQueryParser.java
+++ b/core/src/main/java/org/elasticsearch/index/query/PrefixQueryParser.java
@@ -55,7 +55,7 @@ public class PrefixQueryParser implements QueryParser {
         String rewriteMethod = null;
         String queryName = null;
 
-        Object value = null;
+        String value = null;
         float boost = 1.0f;
         String currentFieldName = null;
         XContentParser.Token token;
@@ -73,7 +73,7 @@ public class PrefixQueryParser implements QueryParser {
                         if ("_name".equals(currentFieldName)) {
                             queryName = parser.text();
                         } else if ("value".equals(currentFieldName) || "prefix".equals(currentFieldName)) {
-                            value = parser.objectBytes();
+                            value = parser.textOrNull();
                         } else if ("boost".equals(currentFieldName)) {
                             boost = parser.floatValue();
                         } else if ("rewrite".equals(currentFieldName)) {
@@ -88,7 +88,7 @@ public class PrefixQueryParser implements QueryParser {
                     queryName = parser.text();
                 } else {
                     fieldName = currentFieldName;
-                    value = parser.objectBytes();
+                    value = parser.textOrNull();
                 }
             }
         }