diff --git a/.travis.yml b/.travis.yml
index 94427c39..1404a76e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,8 +7,9 @@ php:
   - 7.2
 
 env:
-  - SOLR_VERSION=7.5.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.7.x DRUSH_VERSION=~9.4.0
-  - SOLR_VERSION=7.5.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.6.x DRUSH_VERSION=~9.4.0
+  - SOLR_VERSION=7.6.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.7.x DRUSH_VERSION=~9.4.0
+  - SOLR_VERSION=7.6.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.6.x DRUSH_VERSION=~9.4.0
+  - SOLR_VERSION=7.6.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.5.x DRUSH_VERSION=~9.4.0
   - SOLR_VERSION=6.6.5 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=6.x DRUPAL_BRANCH=8.6.x DRUSH_VERSION=~9.4.0
 
 notifications:
@@ -30,6 +31,8 @@ services:
   - mysql
 
 before_install:
+  # Disable xdebug.
+  - cp $HOME/.phpenv/versions/$(phpenv global)/etc/conf.d/xdebug.ini /tmp
   - phpenv config-rm xdebug.ini
   - composer global require "hirak/prestissimo:^0.3"
   - mysql -e 'CREATE DATABASE drupal;'
@@ -58,8 +61,8 @@ install:
   # Patch template.
   #########################################
   # to be removed once #2824932 is resolved
-  #- cd modules/search_api
-  #- curl https://www.drupal.org/files/issues/2824932.patch | patch -p1
+  #- cd modules/contrib/search_api
+  #- curl https://www.drupal.org/files/issues/2018-12-20/3021717.patch | patch -p1
   #- cd $TRAVIS_BUILD_DIR/../drupal
   #########################################
 
@@ -74,7 +77,6 @@ before_script:
   # Install the site.
   - ./vendor/bin/drush -v site-install minimal --db-url=mysql://root:@localhost/drupal --yes
   - ./vendor/bin/drush en --yes drush_language
-  - ./vendor/bin/drush language-add en
   - ./vendor/bin/drush language-add de
   # Let dev versions fullfill module version dependencies.
   - ./vendor/bin/drush en composer_deploy --yes
@@ -96,14 +98,16 @@ before_script:
   - $TRAVIS_BUILD_DIR/solr-${SOLR_VERSION}/bin/solr create -c d8 -d $TRAVIS_BUILD_DIR/solr-${SOLR_VERSION}/server/solr/d8/conf
 
 script:
+  # Re-enable xdebug to support code coverage.
+  - phpenv config-add /tmp/xdebug.ini
   # Run the tests within the drupal directory.
   - cd $TRAVIS_BUILD_DIR/../drupal
-  - ./vendor/bin/phpunit -c core --group search_api_solr --verbose --debug modules/contrib/search_api_solr/tests/src
+  - travis_wait 45 ./vendor/bin/phpunit -c core --group search_api_solr --verbose --debug modules/contrib/search_api_solr/tests/src
 
 matrix:
   exclude:
       - php: 7.0
-        env: SOLR_VERSION=7.5.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.7.x DRUSH_VERSION=~9.4.0
+        env: SOLR_VERSION=7.6.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.7.x DRUSH_VERSION=~9.4.0
   allow_failures:
       - php: 7.2
-        env: SOLR_VERSION=7.5.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.7.x DRUSH_VERSION=~9.4.0
+        env: SOLR_VERSION=7.6.0 SOLR_CORE=d8 SEARCH_API_SOLR_CONF=7.x DRUPAL_BRANCH=8.7.x DRUSH_VERSION=~9.4.0
diff --git a/composer.json b/composer.json
index 0f2b8ff1..aec011a6 100644
--- a/composer.json
+++ b/composer.json
@@ -35,7 +35,7 @@
     },
     "conflict": {
         "drupal/search_api_solr_multilingual": "*",
-        "drupal/core": "<8.6"
+        "drupal/core": "<8.5"
     },
     "suggest": {
         "drupal/facets": "Provides facetted search.",
diff --git a/config/optional/search_api_solr.solr_field_type.text_zh_hans_6_0_0.yml b/config/optional/search_api_solr.solr_field_type.text_zh-hans_6_0_0.yml
similarity index 100%
rename from config/optional/search_api_solr.solr_field_type.text_zh_hans_6_0_0.yml
rename to config/optional/search_api_solr.solr_field_type.text_zh-hans_6_0_0.yml
diff --git a/src/Plugin/search_api/backend/SearchApiSolrAnySchemaBackend.php b/src/Plugin/search_api/backend/SearchApiSolrAnySchemaBackend.php
index 5ed31e99..c3005c0c 100644
--- a/src/Plugin/search_api/backend/SearchApiSolrAnySchemaBackend.php
+++ b/src/Plugin/search_api/backend/SearchApiSolrAnySchemaBackend.php
@@ -206,7 +206,7 @@ public function getSolrFieldNames(IndexInterface $index, $reset = FALSE) {
     }
 
     // Let modules adjust the field mappings.
-    $this->moduleHandler->alter('search_api_solr_field_mapping', $index, $ret);
+    $this->moduleHandler->alter('search_api_solr_field_mapping', $index, $this->fieldNames[$index->id()]);
 
     return $this->fieldNames[$index->id()];
   }