diff --git a/include/etl/algorithm.h b/include/etl/algorithm.h
index d04d24d7..89c6012b 100644
--- a/include/etl/algorithm.h
+++ b/include/etl/algorithm.h
@@ -1928,9 +1928,9 @@ namespace etl
       {
         if (i == etl::find_if(begin1, i, etl::bind1st(predicate, *i)))
         {
-          size_t n = etl::count(begin2, end2, *i);
+          size_t n = etl::count_if(begin2, end2, etl::bind1st(predicate, *i));
 
-          if (n == 0 || size_t(etl::count(i, end1, *i)) != n)
+          if (n == 0 || size_t(etl::count_if(i, end1, etl::bind1st(predicate, *i))) != n)
           {
             return false;
           }
@@ -1954,6 +1954,11 @@ namespace etl
                       TIterator2 begin2,
                       TIterator2 end2)
   {
+    if (etl::distance(begin1, end1) != etl::distance(begin2, end2))
+    {
+      return false;
+    }
+
     if (begin1 != end1)
     {
       for (TIterator1 i = begin1; i != end1; ++i)
@@ -1987,15 +1992,20 @@ namespace etl
                       TIterator2       end2,
                       TBinaryPredicate predicate)
   {
+    if (etl::distance(begin1, end1) != etl::distance(begin2, end2))
+    {
+      return false;
+    }
+
     if (begin1 != end1)
     {
       for (TIterator1 i = begin1; i != end1; ++i)
       {
         if (i == etl::find_if(begin1, i, etl::bind1st(predicate, *i)))
         {
-          size_t n = etl::count(begin2, end2, *i);
+          size_t n = etl::count_if(begin2, end2, etl::bind1st(predicate, *i));
 
-          if (n == 0 || size_t(etl::count(i, end1, *i)) != n)
+          if (n == 0 || size_t(etl::count_if(i, end1, etl::bind1st(predicate, *i))) != n)
           {
             return false;
           }
diff --git a/test/test_algorithm.cpp b/test/test_algorithm.cpp
index 4dd01e9f..3165ad6d 100644
--- a/test/test_algorithm.cpp
+++ b/test/test_algorithm.cpp
@@ -1405,6 +1405,29 @@ namespace
       CHECK(!is_permutation);
     }
 
+    //*************************************************************************
+    TEST(is_permutation_different_lengths)
+    {
+      int shorter[] = { 1, 2 };
+      int longer[]  = { 1, 2, 3 };
+
+      // Four-iterator: range2 longer than range1 (extra elements only in range2)
+      bool result = etl::is_permutation(std::begin(shorter), std::end(shorter), std::begin(longer), std::end(longer));
+      CHECK(!result);
+
+      // Four-iterator: range1 longer than range2
+      result = etl::is_permutation(std::begin(longer), std::end(longer), std::begin(shorter), std::end(shorter));
+      CHECK(!result);
+
+      // Four-iterator with predicate: range2 longer than range1
+      result = etl::is_permutation(std::begin(shorter), std::end(shorter), std::begin(longer), std::end(longer), etl::equal_to<int>());
+      CHECK(!result);
+
+      // Four-iterator with predicate: range1 longer than range2
+      result = etl::is_permutation(std::begin(longer), std::end(longer), std::begin(shorter), std::end(shorter), etl::equal_to<int>());
+      CHECK(!result);
+    }
+
     //*************************************************************************
     TEST(is_partitioned)
     {