diff --git a/src/LambertW.jl b/src/LambertW.jl
index 1af0e89..89cb86e 100644
--- a/src/LambertW.jl
+++ b/src/LambertW.jl
@@ -157,7 +157,7 @@ function lambertw_root_finding(z::T, x0::T, maxits) where T <: Number
         lastx = x
         lastdiff = xdiff
     end
-    converged || warn("lambertw with z=", z, " did not converge in ", maxits, " iterations.")
+    converged || @warn("lambertw with z=", z, " did not converge in ", maxits, " iterations.")
     return x
 end