diff --git a/m-atomic.h b/m-atomic.h
index f5b05895..54ceaa7c 100644
--- a/m-atomic.h
+++ b/m-atomic.h
@@ -332,4 +332,11 @@ M_END_PROTECTED_CODE
 
 #endif
 
+// C17 deprecated ATOMIC_VAR_INIT
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201710L
+# define M_ATOMIC_VAR_INIT(x) (x)
+#else
+# define M_ATOMIC_VAR_INIT(x) ATOMIC_VAR_INIT(x)
+#endif
+
 #endif
diff --git a/m-i-shared.h b/m-i-shared.h
index fcc2af20..f81fa555 100644
--- a/m-i-shared.h
+++ b/m-i-shared.h
@@ -48,11 +48,11 @@ M_BEGIN_PROTECTED_CODE
 
 /* Value of the interface field for static intialization (Uses C99 designated element). */
 #define M_ISHARED_PTR_STATIC_DESIGNATED_INIT(name, type)                      \
-  .M_F(name, _cpt) = ATOMIC_VAR_INIT(0)
+  .M_F(name, _cpt) = M_ATOMIC_VAR_INIT(0)
 
 /* Value of the interface field for static intialization (Uses C89 designated element). */
 #define M_ISHARED_PTR_STATIC_INIT(name, type)                                 \
-  ATOMIC_VAR_INIT(0)
+  M_ATOMIC_VAR_INIT(0)
 
 
 /* Define the intrusive shared pointer type and its M_INLINE functions.
diff --git a/m-thread.h b/m-thread.h
index 0a31f135..4a7da750 100644
--- a/m-thread.h
+++ b/m-thread.h
@@ -681,7 +681,7 @@ typedef struct {
 } m_once_t[1];
 
 // Initial value for m_once_t
-#define M_ONCE_INIT_VALUE            { { ATOMIC_VAR_INIT(0) } }
+#define M_ONCE_INIT_VALUE            { { M_ATOMIC_VAR_INIT(0) } }
 
 // Call the function exactly once
 M_INLINE void m_once_call(m_once_t o, void (*func)(void))
diff --git a/tests/test-mcore.c b/tests/test-mcore.c
index 4f6bf7ff..67a537d2 100644
--- a/tests/test-mcore.c
+++ b/tests/test-mcore.c
@@ -887,13 +887,15 @@ static void test_M_CSTR(void)
 #undef M_USE_CSTR_ALLOC
 #define M_USE_CSTR_ALLOC 8
   // Disable GNUC warning as we want to test this behavior.
-  // this warning is not supported by CLANG
-#if defined (__GNUC__) && __GNUC__ >= 7 && !defined(__clang__)
+  // this warning is supported by CLANG
+#if (defined (__GNUC__) && __GNUC__ >= 7 && !defined(__clang__)) \
+  ||(defined(__clang__) && __clang_major__ >= 18)
   _Pragma("GCC diagnostic push")
   _Pragma("GCC diagnostic ignored \"-Wformat-truncation\"")
 #endif
   r = strcmp(M_CSTR("Hello %s %c", "World", '!'), "Hello W");
-#if defined(__GNUC__) && __GNUC__ >= 7 && !defined(__clang__)
+#if (defined (__GNUC__) && __GNUC__ >= 7 && !defined(__clang__)) \
+  ||(defined(__clang__) && __clang_major__ >= 18)
   _Pragma("GCC diagnostic pop")
 #endif
   assert (r == 0);
diff --git a/tests/test-mworker.c b/tests/test-mworker.c
index 46d6fab4..b79f1622 100644
--- a/tests/test-mworker.c
+++ b/tests/test-mworker.c
@@ -31,7 +31,7 @@ static int fib(int n);
 struct fib2_s {
   int x, n;
 };
-atomic_bool resetFunc_called = ATOMIC_VAR_INIT(false);
+atomic_bool resetFunc_called = M_ATOMIC_VAR_INIT(false);
 static void resetFunc(void)
 {
   atomic_store(&resetFunc_called, true);