Index: apache-tomcat-9.0.19-src/java/org/apache/jasper/compiler/JDTCompiler.java
===================================================================
--- apache-tomcat-9.0.19-src.orig/java/org/apache/jasper/compiler/JDTCompiler.java
+++ apache-tomcat-9.0.19-src/java/org/apache/jasper/compiler/JDTCompiler.java
@@ -312,18 +312,18 @@ public class JDTCompiler extends org.apa
                              CompilerOptions.VERSION_1_7);
             } else if(opt.equals("1.8")) {
                 settings.put(CompilerOptions.OPTION_Source,
-                             CompilerOptions.VERSION_1_8);
+                             "1.8"); // CompilerOptions.VERSION_1_8
             // Version format changed from Java 9 onwards.
             // Support old format that was used in EA implementation as well
             } else if(opt.equals("9") || opt.equals("1.9")) {
                 settings.put(CompilerOptions.OPTION_Source,
-                             CompilerOptions.VERSION_9);
+                             "9"); // CompilerOptions.VERSION_9
             } else if(opt.equals("10")) {
                 settings.put(CompilerOptions.OPTION_Source,
-                             CompilerOptions.VERSION_10);
+                             "10"); // CompilerOptions.VERSION_10
             } else if(opt.equals("11")) {
                 settings.put(CompilerOptions.OPTION_Source,
-                             CompilerOptions.VERSION_11);
+                             "11"); // CompilerOptions.VERSION_11
             } else if(opt.equals("12")) {
                 // Constant not available in latest ECJ version shipped with
                 // Tomcat. May be supported in a snapshot build.
@@ -377,26 +377,26 @@ public class JDTCompiler extends org.apa
                         CompilerOptions.VERSION_1_7);
             } else if(opt.equals("1.8")) {
                 settings.put(CompilerOptions.OPTION_TargetPlatform,
-                             CompilerOptions.VERSION_1_8);
+                             "1.8"); // CompilerOptions.VERSION_1_8
                 settings.put(CompilerOptions.OPTION_Compliance,
-                        CompilerOptions.VERSION_1_8);
+                        "1.8"); // CompilerOptions.VERSION_1_8
             // Version format changed from Java 9 onwards.
             // Support old format that was used in EA implementation as well
             } else if(opt.equals("9") || opt.equals("1.9")) {
                 settings.put(CompilerOptions.OPTION_TargetPlatform,
-                             CompilerOptions.VERSION_9);
+                             "9"); // CompilerOptions.VERSION_9
                 settings.put(CompilerOptions.OPTION_Compliance,
-                        CompilerOptions.VERSION_9);
+                        "9"); // CompilerOptions.VERSION_9
             } else if(opt.equals("10")) {
                 settings.put(CompilerOptions.OPTION_TargetPlatform,
-                        CompilerOptions.VERSION_10);
+                        "10"); // CompilerOptions.VERSION_10
                 settings.put(CompilerOptions.OPTION_Compliance,
-                        CompilerOptions.VERSION_10);
+                        "10"); // CompilerOptions.VERSION_10
             } else if(opt.equals("11")) {
                 settings.put(CompilerOptions.OPTION_TargetPlatform,
-                        CompilerOptions.VERSION_11);
+                        "11"); // CompilerOptions.VERSION_11
                 settings.put(CompilerOptions.OPTION_Compliance,
-                        CompilerOptions.VERSION_11);
+                        "11"); // CompilerOptions.VERSION_11
             } else if(opt.equals("12")) {
                 // Constant not available in latest ECJ version shipped with
                 // Tomcat. May be supported in a snapshot build.