diff --git a/application/argumentparser.cpp b/application/argumentparser.cpp
index 360f440..62a1514 100644
--- a/application/argumentparser.cpp
+++ b/application/argumentparser.cpp
@@ -240,13 +240,13 @@ void ArgumentReader::read(ArgumentVector &args)
             }
         }
 
-        // use the first default argument which is not already present if there is still no match
+        // use the first implicit argument which is not already present if there is still no match
         if (!matchingArg && (!completionMode || (argv + 1 != end))) {
             const bool uncombinableMainArgPresent = parentArg ? false : parser.isUncombinableMainArgPresent();
             for (Argument *arg : args) {
                 if (arg->isImplicit() && !arg->isPresent() && !arg->wouldConflictWithArgument()
                     && (!uncombinableMainArgPresent || !arg->isMainArgument())) {
-                    (matchingArg = arg)->m_occurrences.emplace_back(index, parentPath, parentArg);
+                    (matchingArg = arg)->m_occurrences.emplace_back(Argument::implicitOccurrence, parentPath, parentArg);
                     break;
                 }
             }
diff --git a/application/argumentparser.h b/application/argumentparser.h
index 3fca91c..c5a1b86 100644
--- a/application/argumentparser.h
+++ b/application/argumentparser.h
@@ -245,6 +245,13 @@ public:
      */
     static constexpr std::size_t varValueCount = std::numeric_limits<std::size_t>::max();
 
+    /*!
+     * \brief Indicates an implicit occurrence of an argument.
+     * \return This value is returned by Argument::index() if the argument has been implicitely added.
+     * \sa isImplicit(), setImplicit()
+     */
+    static constexpr std::size_t implicitOccurrence = std::numeric_limits<std::size_t>::max();
+
 private:
     bool matchesDenotation(const char *denotation, size_t denotationLength) const;
 
@@ -556,6 +563,7 @@ inline std::size_t Argument::occurrences() const
 
 /*!
  * \brief Returns the indices of the argument's occurences which could be detected when parsing.
+ * \remarks Might return Argument::implicitOccurrence in case the argument has been implicitely added.
  */
 inline std::size_t Argument::index(std::size_t occurrence) const
 {