diff --git a/OpenCL/inc_vendor.h b/OpenCL/inc_vendor.h
index c39fce952..0916a30b3 100644
--- a/OpenCL/inc_vendor.h
+++ b/OpenCL/inc_vendor.h
@@ -12,7 +12,7 @@
 #define IS_CUDA
 #elif defined __HIPCC__
 #define IS_HIP
-#elif defined __METAL_MACOS__
+#elif defined __METAL__
 #define IS_METAL
 #else
 #define IS_OPENCL
diff --git a/src/backend.c b/src/backend.c
index 3c63882e1..8aa8c587c 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -4503,7 +4503,19 @@ int backend_ctx_init (hashcat_ctx_t *hashcat_ctx)
 
       if (hc_mtlRuntimeGetVersionString (hashcat_ctx, backend_ctx->metal_runtimeVersionStr, &version_len) == -1) return -1;
 
-      // TODO: needs version check
+      if (atoi (backend_ctx->metal_runtimeVersionStr) < 300)
+      {
+        event_log_warning (hashcat_ctx, "Unsupported Apple Metal runtime version '%s' detected! Falling back to OpenCL...", backend_ctx->metal_runtimeVersionStr);
+        event_log_warning (hashcat_ctx, NULL);
+
+        rc_metal_init = -1;
+
+        backend_ctx->rc_metal_init = rc_metal_init;
+
+        backend_ctx->mtl = NULL;
+
+        mtl_close (hashcat_ctx);
+      }
     }
     else
     {
@@ -4511,6 +4523,8 @@ int backend_ctx_init (hashcat_ctx_t *hashcat_ctx)
 
       backend_ctx->rc_metal_init = rc_metal_init;
 
+      backend_ctx->mtl = NULL;
+
       mtl_close (hashcat_ctx);
     }
   }
@@ -9265,8 +9279,11 @@ int backend_session_begin (hashcat_ctx_t *hashcat_ctx)
     {
       // set some limits with Metal
 
-      device_param->kernel_threads_max = 128;
+      device_param->kernel_threads_max = 64;
+      device_param->kernel_threads_min = MIN (device_param->kernel_threads_min, device_param->kernel_threads_max);
+
       device_param->kernel_loops_max = 1024;  // autotune go over ...
+      device_param->kernel_loops_min = MIN (device_param->kernel_loops_min, device_param->kernel_loops_max);
     }
     #endif