diff --git a/src/libs/utils/icon.cpp b/src/libs/utils/icon.cpp
index f0b42e2f936..6d585518f15 100644
--- a/src/libs/utils/icon.cpp
+++ b/src/libs/utils/icon.cpp
@@ -166,7 +166,7 @@ Icon::Icon(std::initializer_list<IconMaskAndColor> args, Icon::IconStyleOptions
 Icon::Icon(std::initializer_list<IconStringMaskAndColor> args, Icon::IconStyleOptions style)
     : m_style(style)
 {
-    reserve(args.size());
+    reserve(int(args.size()));
     for (const IconStringMaskAndColor &i : args)
         append({FilePath::fromString(i.first), i.second});
 }