diff --git a/SteamStorefrontAPI/Endpoints/AppDetails.cs b/SteamStorefrontAPI/Endpoints/AppDetails.cs
index d686d98..0a09f24 100644
--- a/SteamStorefrontAPI/Endpoints/AppDetails.cs
+++ b/SteamStorefrontAPI/Endpoints/AppDetails.cs
@@ -16,19 +16,19 @@ namespace SteamStorefrontAPI
 
         public static async Task<SteamApp> GetAsync(int AppId)
         {
-            return await GetAsync(AppId, null, null);
+            return await GetAsync(AppId, "", "");
         }
 
         public static async Task<SteamApp> GetAsync(int AppId, string CountryCode)
         {
-            return await GetAsync(AppId, CountryCode, null);
+            return await GetAsync(AppId, CountryCode, "");
         }
 
         public static async Task<SteamApp> GetAsync(int AppId, string CountryCode, string Language)
         {
             string steamUri = $"{steamBaseUri}?appids={AppId}";
-            steamUri = CountryCode is null ? steamUri : $"{steamUri}&cc={CountryCode}";
-            steamUri = Language is null ? steamUri : $"{steamUri}&l={Language}";
+            steamUri = string.IsNullOrWhiteSpace(CountryCode) ? steamUri : $"{steamUri}&cc={CountryCode}";
+            steamUri = string.IsNullOrWhiteSpace(Language) ? steamUri : $"{steamUri}&l={Language}";
 
             var response = await client.GetAsync(steamUri);
             if (!response.IsSuccessStatusCode) { return null; }
diff --git a/SteamStorefrontAPI/Endpoints/Featured.cs b/SteamStorefrontAPI/Endpoints/Featured.cs
index 93ab539..a9f7220 100644
--- a/SteamStorefrontAPI/Endpoints/Featured.cs
+++ b/SteamStorefrontAPI/Endpoints/Featured.cs
@@ -28,8 +28,8 @@ namespace SteamStorefrontAPI
         public static async Task<FeaturedApps> GetAsync(string CountryCode, string Language)
         {
             string steamUri = steamBaseUri;
-            steamUri = CountryCode is null ? steamUri : $"{steamUri}&cc={CountryCode}";
-            steamUri = Language is null ? steamUri : $"{steamUri}&l={Language}";
+            steamUri = string.IsNullOrWhiteSpace(CountryCode) ? steamUri : $"{steamUri}&cc={CountryCode}";
+            steamUri = string.IsNullOrWhiteSpace(Language) ? steamUri : $"{steamUri}&l={Language}";
 
             var response = await client.GetAsync(steamUri);
             if (!response.IsSuccessStatusCode) { return null; }
diff --git a/SteamStorefrontAPI/Endpoints/FeaturedCategories.cs b/SteamStorefrontAPI/Endpoints/FeaturedCategories.cs
index ec07e45..1724392 100644
--- a/SteamStorefrontAPI/Endpoints/FeaturedCategories.cs
+++ b/SteamStorefrontAPI/Endpoints/FeaturedCategories.cs
@@ -27,8 +27,8 @@ namespace SteamStorefrontAPI
         public static async Task<List<FeaturedCategory>> GetAsync(string CountryCode, string Language)
         {
             string steamUri = steamBaseUri;
-            steamUri = CountryCode is null ? steamUri : $"{steamUri}&cc={CountryCode}";
-            steamUri = Language is null ? steamUri : $"{steamUri}&l={Language}";
+            steamUri = string.IsNullOrWhiteSpace(CountryCode) ? steamUri : $"{steamUri}&cc={CountryCode}";
+            steamUri = string.IsNullOrWhiteSpace(Language) ? steamUri : $"{steamUri}&l={Language}";
 
             var response = await client.GetAsync(steamUri);
             if (!response.IsSuccessStatusCode) { return null; }
diff --git a/SteamStorefrontAPI/Endpoints/PackageDetails.cs b/SteamStorefrontAPI/Endpoints/PackageDetails.cs
index 4d952e2..0093ce9 100644
--- a/SteamStorefrontAPI/Endpoints/PackageDetails.cs
+++ b/SteamStorefrontAPI/Endpoints/PackageDetails.cs
@@ -27,8 +27,8 @@ namespace SteamStorefrontAPI
         public static async Task<PackageInfo> GetAsync(int PackageId, string CountryCode, string Language)
         {
             string steamUri = $"{steamBaseUri}?packageids={PackageId}";
-            steamUri = CountryCode is null ? steamUri : $"{steamUri}&cc={CountryCode}";
-            steamUri = Language is null ? steamUri : $"{steamUri}&l={Language}";
+            steamUri = string.IsNullOrWhiteSpace(CountryCode) ? steamUri : $"{steamUri}&cc={CountryCode}";
+            steamUri = string.IsNullOrWhiteSpace(Language) ? steamUri : $"{steamUri}&l={Language}";
 
             var response = await client.GetAsync(steamUri);
             if (!response.IsSuccessStatusCode) { return null; }