diff --git a/src/layer/vulkan/shader/unaryop.comp b/src/layer/vulkan/shader/unaryop.comp
index 524e911fe..c17960816 100644
--- a/src/layer/vulkan/shader/unaryop.comp
+++ b/src/layer/vulkan/shader/unaryop.comp
@@ -41,7 +41,7 @@ void main()
     if (op_type == 14) res = atan(v);
     if (op_type == 15) res = afp(1.f) / v;
 #if NCNN_moltenvk
-    if (op_type == 16) res = afp(tanh(float(v)));
+    if (op_type == 16) res = afpvec4(tanh(vec4(v)));
 #else
     if (op_type == 16) res = tanh(v);
 #endif