diff --git a/solr-conf/4.x/schema.xml b/solr-conf/4.x/schema.xml
index b2c566a..16f468a 100644
--- a/solr-conf/4.x/schema.xml
+++ b/solr-conf/4.x/schema.xml
@@ -10,7 +10,7 @@
  http://wiki.apache.org/solr/SchemaXml
 -->
 
-<schema name="drupal-4.4-solr-4.x" version="1.3">
+<schema name="drupal-4.5-solr-4.x" version="1.3">
     <!-- attribute "name" is the name of this schema and is only used for display purposes.
          Applications should change this to reflect the nature of the search collection.
          version="1.2" is Solr's version number for the schema syntax and semantics.  It should
@@ -34,10 +34,10 @@
        limits compression (if enabled in the derived fields) to values which
        exceed a certain size (in characters).
     -->
-    <fieldType name="string" class="solr.StrField" sortMissingLast="true" omitNorms="true"/>
+    <fieldType name="string" class="solr.StrField" omitNorms="true"/>
 
     <!-- boolean type: "true" or "false" -->
-    <fieldType name="boolean" class="solr.BoolField" sortMissingLast="true" omitNorms="true"/>
+    <fieldType name="boolean" class="solr.BoolField" omitNorms="true"/>
     <!--Binary data type. The data should be sent/retrieved in as Base64 encoded Strings -->
     <fieldtype name="binary" class="solr.BinaryField"/>
 
@@ -119,7 +119,7 @@
 
          Consult the DateField javadocs for more information.
       -->
-    <fieldType name="date" class="solr.DateField" sortMissingLast="true" omitNorms="true"/>
+    <fieldType name="date" class="solr.DateField" omitNorms="true"/>
 
     <!-- A Trie based date field for faster date range queries and date faceting. -->
     <fieldType name="tdate" class="solr.TrieDateField" omitNorms="true" precisionStep="6" positionIncrementGap="0"/>
@@ -281,7 +281,7 @@
          With various TokenFilterFactories to produce a sortable field
          that does not include some properties of the source text
       -->
-    <fieldType name="sortString" class="solr.TextField" sortMissingLast="true" omitNorms="true">
+    <fieldType name="sortString" class="solr.TextField" omitNorms="true">
       <analyzer>
         <!-- KeywordTokenizer does no actual tokenizing, so the entire
             input string is preserved as a single token
diff --git a/solr-conf/5.x/schema.xml b/solr-conf/5.x/schema.xml
index 3d47656..c9da61b 100644
--- a/solr-conf/5.x/schema.xml
+++ b/solr-conf/5.x/schema.xml
@@ -10,7 +10,7 @@
  http://wiki.apache.org/solr/SchemaXml
 -->
 
-<schema name="drupal-4.4-solr-5.x" version="1.5">
+<schema name="drupal-4.5-solr-5.x" version="1.5">
     <!-- attribute "name" is the name of this schema and is only used for
          display purposes. Applications should change this to reflect the nature
          of the search collection.
@@ -44,10 +44,10 @@
        limits compression (if enabled in the derived fields) to values which
        exceed a certain size (in characters).
     -->
-    <fieldType name="string" class="solr.StrField" sortMissingLast="true"/>
+    <fieldType name="string" class="solr.StrField"/>
 
     <!-- boolean type: "true" or "false" -->
-    <fieldType name="boolean" class="solr.BoolField" sortMissingLast="true"/>
+    <fieldType name="boolean" class="solr.BoolField"/>
     <!--Binary data type. The data should be sent/retrieved in as Base64 encoded Strings -->
     <fieldtype name="binary" class="solr.BinaryField"/>
 
@@ -130,7 +130,7 @@
 
          Note: For faster range queries, consider the tdate type
       -->
-    <fieldType name="date" class="solr.TrieDateField" precisionStep="0" positionIncrementGap="0" sortMissingLast="true" omitNorms="true"/>
+    <fieldType name="date" class="solr.TrieDateField" precisionStep="0" positionIncrementGap="0" omitNorms="true"/>
 
     <!-- A Trie based date field for faster date range queries and date faceting. -->
     <fieldType name="tdate" class="solr.TrieDateField" precisionStep="6" positionIncrementGap="0"/>
@@ -326,7 +326,7 @@
          With various TokenFilterFactories to produce a sortable field
          that does not include some properties of the source text
       -->
-    <fieldType name="sortString" class="solr.TextField" sortMissingLast="true" omitNorms="true">
+    <fieldType name="sortString" class="solr.TextField" omitNorms="true">
       <analyzer>
         <!-- KeywordTokenizer does no actual tokenizing, so the entire
             input string is preserved as a single token
diff --git a/solr-conf/6.x/schema.xml b/solr-conf/6.x/schema.xml
index a901573..4b53e70 100755
--- a/solr-conf/6.x/schema.xml
+++ b/solr-conf/6.x/schema.xml
@@ -51,7 +51,7 @@
     that avoids logging every request
 -->
 
-<schema name="drupal-5.2-solr-6.x" version="1.6">
+<schema name="drupal-5.3-solr-6.x" version="1.6">
   <!-- attribute "name" is the name of this schema and is only used for display purposes.
        version="x.y" is Solr's version number for the schema syntax and
        semantics.  It should not normally be changed by applications.
@@ -273,10 +273,10 @@
        It supports doc values but in that case the field needs to be
        single-valued and either required or have a default value.
       -->
-    <fieldType name="string" class="solr.StrField" sortMissingLast="true" />
+    <fieldType name="string" class="solr.StrField"/>
 
     <!-- boolean type: "true" or "false" -->
-    <fieldType name="boolean" class="solr.BoolField" sortMissingLast="true"/>
+    <fieldType name="boolean" class="solr.BoolField"/>
 
     <!-- sortMissingLast and sortMissingFirst attributes are optional attributes are
          currently supported on types that are sorted internally as strings
@@ -350,7 +350,7 @@
 
          Note: For faster range queries, consider the tdate type
       -->
-    <fieldType name="date" class="solr.TrieDateField" precisionStep="0" positionIncrementGap="0" sortMissingLast="true" omitNorms="true"/>
+    <fieldType name="date" class="solr.TrieDateField" precisionStep="0" positionIncrementGap="0" omitNorms="true"/>
 
     <!-- A Trie based date field for faster date range queries and date faceting. -->
     <fieldType name="tdate" class="solr.TrieDateField" precisionStep="6" positionIncrementGap="0"/>
@@ -564,7 +564,7 @@
          With various TokenFilterFactories to produce a sortable field
          that does not include some properties of the source text
       -->
-    <fieldType name="alphaOnlySort" class="solr.TextField" sortMissingLast="true" omitNorms="true">
+    <fieldType name="alphaOnlySort" class="solr.TextField" omitNorms="true">
       <analyzer>
         <!-- KeywordTokenizer does no actual tokenizing, so the entire
              input string is preserved as a single token
@@ -598,7 +598,7 @@
          characters, numbers and punctuation, for example
          'entity:entity_test_mulrev_changed/2:en'.
      -->
-    <fieldType name="sortString" class="solr.TextField" sortMissingLast="true" omitNorms="true">
+    <fieldType name="sortString" class="solr.TextField" omitNorms="true">
       <analyzer>
         <!-- KeywordTokenizer does no actual tokenizing, so the entire
             input string is preserved as a single token
diff --git a/tests/src/Kernel/SearchApiSolrTest.php b/tests/src/Kernel/SearchApiSolrTest.php
index 3248a07..105efdd 100644
--- a/tests/src/Kernel/SearchApiSolrTest.php
+++ b/tests/src/Kernel/SearchApiSolrTest.php
@@ -668,7 +668,7 @@ class SearchApiSolrTest extends BackendTestBase {
         // Force an expected order for identical keywords.
         ->sort('search_api_id')
         ->execute();
-      $this->assertResults([4, 1, 2, 5, 3, 6, 7], $results, 'Sort by keywords.');
+      $this->assertResults([3, 6, 7, 4, 1, 2, 5], $results, 'Sort by keywords.');
 
       $results = $this->buildSearch(NULL, [], [], FALSE)
         ->sort('keywords', QueryInterface::SORT_DESC)
@@ -683,9 +683,6 @@ class SearchApiSolrTest extends BackendTestBase {
         // Force an expected order for identical width.
         ->sort('search_api_id')
         ->execute();
-      // @todo if width is missing it seems to be treated like 0 because
-      //   sortMissingLast="true" doesn't fix it.
-      // $this->assertResults([4, 5, 1, 2, 3], $results, 'Sort by width.');
       $this->assertResults([1, 2, 3, 6, 7, 4, 5], $results, 'Sort by width.');
 
       $results = $this->buildSearch(NULL, [], [], FALSE)