diff --git a/lib/src/main/java/com/uwyn/urlencoder/UrlEncoder.java b/lib/src/main/java/com/uwyn/urlencoder/UrlEncoder.java
index 3fbcfe0..3486188 100644
--- a/lib/src/main/java/com/uwyn/urlencoder/UrlEncoder.java
+++ b/lib/src/main/java/com/uwyn/urlencoder/UrlEncoder.java
@@ -237,9 +237,9 @@ public final class UrlEncoder {
             var option = args.remove(0);
             if (option.equals("-d")) {
                 perform_decode = true;
-                valid_arguments = !args.isEmpty();
+                valid_arguments = (args.size() == 1);
             } else if (option.equals("-e")) {
-                valid_arguments = !args.isEmpty();
+                valid_arguments = (args.size() == 1);
             } else {
                 args.clear();
             }
diff --git a/lib/src/test/java/com/uwyn/urlencoder/UrlEncoderTest.java b/lib/src/test/java/com/uwyn/urlencoder/UrlEncoderTest.java
index f0f67a7..a095b35 100644
--- a/lib/src/test/java/com/uwyn/urlencoder/UrlEncoderTest.java
+++ b/lib/src/test/java/com/uwyn/urlencoder/UrlEncoderTest.java
@@ -94,6 +94,20 @@ class UrlEncoderTest {
         assertTrue(result.output.contains("Usage :"));
     }
 
+    @Test
+    void testMainWrongArgs4() {
+        var result = UrlEncoder.processMain(new String[] {"-d", "stuff", "txt"});
+        assertEquals(1, result.status);
+        assertTrue(result.output.contains("Usage :"));
+    }
+
+    @Test
+    void testMainWrongArgs5() {
+        var result = UrlEncoder.processMain(new String[] {"-e", "stuff", "txt"});
+        assertEquals(1, result.status);
+        assertTrue(result.output.contains("Usage :"));
+    }
+
     @Test
     void testDecodeMainOption() {
         validMap.forEach((expected, source) -> {