diff --git a/src/main/java/org/apache/bcel/generic/MethodGen.java b/src/main/java/org/apache/bcel/generic/MethodGen.java
index f3bc120ef7..f928f42bbc 100644
--- a/src/main/java/org/apache/bcel/generic/MethodGen.java
+++ b/src/main/java/org/apache/bcel/generic/MethodGen.java
@@ -1192,7 +1192,8 @@ public void setInstructionList(final InstructionList il) { // TODO could be pack
     }
 
     /**
-     * Sets the maximum number of local variables by examining the method signature and instructions.
+     * Sets the maximum number of local variables by examining the method signature, the instructions and the local
+     * variable table entries added via {@link #addLocalVariable}.
      */
     public void setMaxLocals() { // TODO could be package-protected? (some tests would need repackaging)
         if (il != null) {
@@ -1209,6 +1210,15 @@ public void setMaxLocals() { // TODO could be package-protected? (some tests wou
                     }
                 }
             }
+            // Local variables may be registered (for example, copied from an existing LocalVariableTable) without
+            // being referenced by any instruction, e.g. unused variables emitted by some compilers. Account for
+            // those too, so a later call does not shrink maxLocals below what those entries require.
+            for (final LocalVariableGen lv : variableList) {
+                final int index = lv.getIndex() + lv.getType().getSize();
+                if (index > max) {
+                    max = index;
+                }
+            }
             maxLocals = max;
         } else {
             maxLocals = 0;
diff --git a/src/test/java/org/apache/bcel/generic/MethodGenTest.java b/src/test/java/org/apache/bcel/generic/MethodGenTest.java
index 6cbd721061..b8cb5ee74f 100644
--- a/src/test/java/org/apache/bcel/generic/MethodGenTest.java
+++ b/src/test/java/org/apache/bcel/generic/MethodGenTest.java
@@ -30,6 +30,7 @@
 import java.util.Arrays;
 import java.util.List;
 
+import org.apache.bcel.Const;
 import org.apache.bcel.Repository;
 import org.apache.bcel.classfile.JavaClass;
 import org.apache.bcel.classfile.Method;
@@ -143,4 +144,29 @@ void testRemoveLocalVariables() throws Exception {
         assertNull(lv.getStart(), "scope start");
         assertNull(lv.getEnd(), "scope end");
     }
+
+    @Test
+    void testSetMaxLocalsAccountsForLocalVariableTable() {
+        // BCEL-280: some compilers (e.g. kotlinc) emit LocalVariableTable entries for slots that no
+        // instruction in the method body ever touches. setMaxLocals() must not shrink maxLocals below
+        // what those entries require, or the resulting class file fails verification with a
+        // "Invalid index ... in LocalVariableTable" ClassFormatError.
+        final InstructionList il = new InstructionList();
+        il.append(InstructionConst.ALOAD_0);
+        il.append(InstructionConst.RETURN);
+
+        final MethodGen mg = new MethodGen(Const.ACC_PUBLIC, Type.VOID, Type.NO_ARGS, new String[0], "bar", "Foo", il,
+            new ConstantPoolGen());
+
+        final InstructionHandle start = il.getStart();
+        final InstructionHandle end = il.getEnd();
+        // Slot 6 is only referenced through the local variable table below, never by an instruction.
+        mg.addLocalVariable("unusedByCompiler", Type.INT, 6, start, end);
+        assertEquals(7, mg.getMaxLocals(), "addLocalVariable() should already have grown maxLocals");
+
+        // Simulate a later pass (e.g. instrumentation) recomputing maxLocals from the instruction list.
+        mg.setMaxLocals();
+
+        assertEquals(7, mg.getMaxLocals(), "setMaxLocals() dropped a local variable table entry unreferenced by instructions");
+    }
 }