diff --git a/desktop_version/src/UtilityClass.cpp b/desktop_version/src/UtilityClass.cpp
index e0700f7e..6e1c96a9 100644
--- a/desktop_version/src/UtilityClass.cpp
+++ b/desktop_version/src/UtilityClass.cpp
@@ -272,7 +272,7 @@ bool is_number(const char* str)
 		return false;
 	}
 
-	for (int i = 1; str[i] != '\0'; i++)
+	for (size_t i = 1; str[i] != '\0'; i++)
 	{
 		if (!SDL_isdigit(str[i]))
 		{