diff -up ./java/org/apache/jasper/compiler/JDTCompiler.java ./java/org/apache/jasper/compiler/JDTCompiler.java
index 2e361f2..277d8f4 100644
--- java/org/apache/jasper/compiler/JDTCompiler.java
+++ java/org/apache/jasper/compiler/JDTCompiler.java
@@ -310,7 +310,7 @@ public class JDTCompiler extends org.apache.jasper.compiler.Compiler {
             } else if(opt.equals("15")) {
                 settings.put(CompilerOptions.OPTION_Source, CompilerOptions.VERSION_15);
             } else if(opt.equals("16")) {
-                settings.put(CompilerOptions.OPTION_Source, CompilerOptions.VERSION_16);
+                settings.put(CompilerOptions.OPTION_Source, "16");
             } else if(opt.equals("17")) {
                 // Constant not available in latest ECJ version that runs on
                 // Java 8.
@@ -377,8 +377,8 @@ public class JDTCompiler extends org.apache.jasper.compiler.Compiler {
                 settings.put(CompilerOptions.OPTION_TargetPlatform, CompilerOptions.VERSION_15);
                 settings.put(CompilerOptions.OPTION_Compliance, CompilerOptions.VERSION_15);
             } else if(opt.equals("16")) {
-                settings.put(CompilerOptions.OPTION_TargetPlatform, CompilerOptions.VERSION_16);
-                settings.put(CompilerOptions.OPTION_Compliance, CompilerOptions.VERSION_16);
+                settings.put(CompilerOptions.OPTION_TargetPlatform, "16");
+                settings.put(CompilerOptions.OPTION_Compliance, "16");
             } else if(opt.equals("17")) {
                 // Constant not available in latest ECJ version that runs on
                 // Java 8.