diff --git a/src/mbgl/style/expression/compound_expression.cpp b/src/mbgl/style/expression/compound_expression.cpp
index bae0258aa..defe9ea5a 100644
--- a/src/mbgl/style/expression/compound_expression.cpp
+++ b/src/mbgl/style/expression/compound_expression.cpp
@@ -101,7 +101,7 @@ private:
     template <std::size_t ...I>
     EvaluationResult applyImpl(const EvaluationContext& evaluationParameters, const Args& args, std::index_sequence<I...>) const {
         std::array<Value, sizeof...(Params)> evaluated;
-        for (std::size_t i = 0; i < sizeof...(Params); ++i) {
+        for (int i = 0; i < int(sizeof...(Params)); ++i) {
             const EvaluationResult evaluatedArg = args.at(i)->evaluate(evaluationParameters);
             if (!evaluatedArg) return evaluatedArg.error();
             evaluated[i] = *evaluatedArg;
@@ -155,7 +155,7 @@ private:
     template <std::size_t ...I>
     EvaluationResult applyImpl(const EvaluationContext& evaluationParameters, const Args& args, std::index_sequence<I...>) const {
         std::array<Value, sizeof...(Params)> evaluated;
-        for (std::size_t i = 0; i < sizeof...(Params); ++i) {
+        for (int i = 0; i < int(sizeof...(Params)); ++i) {
             const EvaluationResult evaluatedArg = args.at(i)->evaluate(evaluationParameters);
             if (!evaluatedArg) return evaluatedArg.error();
             evaluated[i] = *evaluatedArg;