diff --git a/lib/src/Base/Type/Indices.cxx b/lib/src/Base/Type/Indices.cxx
index 3791b352f8..6853ae8d20 100644
--- a/lib/src/Base/Type/Indices.cxx
+++ b/lib/src/Base/Type/Indices.cxx
@@ -52,6 +52,16 @@ Bool Indices::isIncreasing() const
   return true;
 }
 
+/* Check if the indices are strictly increasing */
+Bool Indices::isStrictlyIncreasing() const
+{
+  const UnsignedInteger size = getSize();
+  if (!(size > 1)) return true;
+  for (UnsignedInteger i = 1; i < size; ++i)
+    if (operator[](i) <= operator[](i - 1)) return false;
+  return true;
+}
+
 /* Fill the indices with a linear progression, starting from start value by step stepsize */
 void Indices::fill(const UnsignedInteger initialValue,
                    const UnsignedInteger stepSize)
diff --git a/lib/src/Base/Type/openturns/Indices.hxx b/lib/src/Base/Type/openturns/Indices.hxx
index 86ccfd43b3..7d4e01a0be 100644
--- a/lib/src/Base/Type/openturns/Indices.hxx
+++ b/lib/src/Base/Type/openturns/Indices.hxx
@@ -81,6 +81,9 @@ public:
   /** Check if the indices are increasing */
   Bool isIncreasing() const;
 
+  /** Check if the indices are strictly increasing */
+  Bool isStrictlyIncreasing() const;
+
   /** Fill the indices with a linear progression, starting from start value by step stepsize */
   void fill(const UnsignedInteger initialValue = 0,
             const UnsignedInteger stepSize = 1);