diff --git a/src/metric/elementwise_metric.cc b/src/metric/elementwise_metric.cc
index 515a69b6b..f022c8130 100644
--- a/src/metric/elementwise_metric.cc
+++ b/src/metric/elementwise_metric.cc
@@ -124,7 +124,7 @@ struct EvalError : public EvalEWiseBase<EvalError> {
   std::string name_;
 };
 
-struct EvalPoissionNegLogLik : public EvalEWiseBase<EvalPoissionNegLogLik> {
+struct EvalPoissonNegLogLik : public EvalEWiseBase<EvalPoissonNegLogLik> {
   const char *Name() const override {
     return "poisson-nloglik";
   }
@@ -205,7 +205,7 @@ XGBOOST_REGISTER_METRIC(Error, "error")
 
 XGBOOST_REGISTER_METRIC(PossionNegLoglik, "poisson-nloglik")
 .describe("Negative loglikelihood for poisson regression.")
-.set_body([](const char* param) { return new EvalPoissionNegLogLik(); });
+.set_body([](const char* param) { return new EvalPoissonNegLogLik(); });
 
 XGBOOST_REGISTER_METRIC(GammaDeviance, "gamma-deviance")
 .describe("Residual deviance for gamma regression.")