diff --git a/test/test_const_multiset.cpp b/test/test_const_multiset.cpp
index ae97994b..ad54fadf 100644
--- a/test/test_const_multiset.cpp
+++ b/test/test_const_multiset.cpp
@@ -85,11 +85,13 @@ namespace
     return (lhs.k == rhs.k);
   }
 
+#if !defined(ETL_DEVELOPMENT_OS_APPLE)
   // Equality operator for Key != Key
   constexpr bool operator !=(const Key& lhs, const Key& rhs) noexcept
   {
     return !(lhs.k == rhs.k);
   }
+#endif
 
 #define TEST_GREATER_THAN
 #ifdef TEST_GREATER_THAN
diff --git a/test/test_const_multiset_ext.cpp b/test/test_const_multiset_ext.cpp
index a05fef54..2c899cac 100644
--- a/test/test_const_multiset_ext.cpp
+++ b/test/test_const_multiset_ext.cpp
@@ -86,11 +86,13 @@ namespace
     return (lhs.k == rhs.k);
   }
 
+#if !defined(ETL_DEVELOPMENT_OS_APPLE)
   // Equality operator for Key != Key
   constexpr bool operator !=(const Key& lhs, const Key& rhs) noexcept
   {
     return !(lhs.k == rhs.k);
   }
+#endif
 
 #define TEST_GREATER_THAN
 #ifdef TEST_GREATER_THAN
diff --git a/test/test_const_multiset_ext_constexpr.cpp b/test/test_const_multiset_ext_constexpr.cpp
index e04d79b7..03509be6 100644
--- a/test/test_const_multiset_ext_constexpr.cpp
+++ b/test/test_const_multiset_ext_constexpr.cpp
@@ -88,11 +88,13 @@ namespace
     return (lhs.k == rhs.k);
   }
 
+#if !defined(ETL_DEVELOPMENT_OS_APPLE)
   // Equality operator for Key != Key
   constexpr bool operator !=(const Key& lhs, const Key& rhs) noexcept
   {
     return !(lhs.k == rhs.k);
   }
+#endif
 
 #define TEST_GREATER_THAN
 #ifdef TEST_GREATER_THAN