diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 6aad633..83104a0 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java_version: ['11', '17']
+        java_version: ['11', '17', '20']
         os: [ubuntu-latest, windows-latest, macOS-latest]
     steps:
     - uses: actions/checkout@v3
diff --git a/src/main/java/com/github/_1c_syntax/bsl/supconf/SupportConfiguration.java b/src/main/java/com/github/_1c_syntax/bsl/supconf/SupportConfiguration.java
index 6ecc12b..a2e628b 100644
--- a/src/main/java/com/github/_1c_syntax/bsl/supconf/SupportConfiguration.java
+++ b/src/main/java/com/github/_1c_syntax/bsl/supconf/SupportConfiguration.java
@@ -60,7 +60,7 @@ public int compareTo(SupportConfiguration o) {
     }
   }
 
-  private String stripQuotes(String value) {
+  private static String stripQuotes(String value) {
     if(value == null || value.length() < 2) {
       return value;
     }