--- tmp/org/eclipse/jdt/internal/compiler/batch/GCCMain.java.0	2013-12-10 18:06:44.008832640 +0200
+++ tmp/org/eclipse/jdt/internal/compiler/batch/GCCMain.java	2017-11-18 18:16:28.863241724 +0200
@@ -248,7 +248,7 @@
 			if (!(entry.getValue() instanceof String))
 				continue;
 			if (((String) entry.getValue()).equals(CompilerOptions.WARNING)) {
-				this.options.put(entry.getKey(), CompilerOptions.ERROR);
+				this.options.put((String) entry.getKey(), CompilerOptions.ERROR);
 			}
 		}
 	}