diff --git a/substrate/srml/support/procedural/src/storage/transformation.rs b/substrate/srml/support/procedural/src/storage/transformation.rs
index 1e0141615f..146210eb0c 100644
--- a/substrate/srml/support/procedural/src/storage/transformation.rs
+++ b/substrate/srml/support/procedural/src/storage/transformation.rs
@@ -198,7 +198,7 @@ fn decl_store_extra_genesis(
 
 	let mut is_trait_needed = false;
 	let mut has_trait_field = false;
-	let mut serde_complete_bound = std::collections::HashSet::new();
+	let mut serde_complete_bound = Vec::new();
 	let mut config_field = TokenStream2::new();
 	let mut config_field_default = TokenStream2::new();
 	let mut builders = TokenStream2::new();
@@ -239,9 +239,20 @@ fn decl_store_extra_genesis(
 				has_trait_field = true;
 			}
 
-			serde_complete_bound.insert(type_infos.value_type);
-			if let DeclStorageTypeInfosKind::Map { key_type, .. } = type_infos.kind {
-				serde_complete_bound.insert(key_type);
+			let value_type = &type_infos.value_type;
+			serde_complete_bound.push(quote!( #value_type ));
+			match type_infos.kind {
+				DeclStorageTypeInfosKind::Map { key_type, .. } =>
+					serde_complete_bound.push(quote!( #key_type )),
+				DeclStorageTypeInfosKind::DoubleMap { key1_type, key2_type, .. } => {
+					serde_complete_bound.push(quote!( #key1_type ));
+					serde_complete_bound.push(quote!( #key2_type ));
+				},
+				_ => {},
+			}
+
+			if type_infos.is_option {
+				serde_complete_bound.push(type_infos.typ.clone());
 			}
 
 			// Propagate doc attributes.
@@ -335,7 +346,7 @@ fn decl_store_extra_genesis(
 						has_trait_field = true;
 					}
 
-					serde_complete_bound.insert(extra_type);
+					serde_complete_bound.push(quote!( #extra_type ));
 
 					let extrafield = &extra_field.content;
 					genesis_extrafields.extend(quote!{
@@ -363,7 +374,7 @@ fn decl_store_extra_genesis(
 	let serde_bug_bound = if !serde_complete_bound.is_empty() {
 		let mut b_ser = String::new();
 		let mut b_dser = String::new();
-		// panic!("{:#?}", serde_complete_bound);
+
 		serde_complete_bound.into_iter().for_each(|bound| {
 			let stype = quote!(#bound);
 			b_ser.push_str(&format!("{} : {}::serde::Serialize, ", stype, scrate));
@@ -515,7 +526,7 @@ fn decl_storage_items(
 
 			impls.extend(quote! {
 				/// Tag a type as an instance of a module.
-				/// 
+				///
 				/// Defines storage prefixes, they must be unique.
 				pub trait #instantiable: 'static {
 					#const_impls
diff --git a/substrate/srml/support/test/tests/final_keys.rs b/substrate/srml/support/test/tests/final_keys.rs
index 69b815e10a..549506df49 100644
--- a/substrate/srml/support/test/tests/final_keys.rs
+++ b/substrate/srml/support/test/tests/final_keys.rs
@@ -18,11 +18,11 @@ use runtime_io::{with_externalities, Blake2Hasher};
 use srml_support::{StorageValue, StorageMap, StorageDoubleMap};
 use srml_support::storage::unhashed;
 use srml_support::runtime_primitives::BuildStorage;
-use parity_codec::Encode;
+use parity_codec::{Encode, Decode};
 
 pub trait Trait {
 	type Origin;
-	type BlockNumber;
+	type BlockNumber: Encode + Decode + Default + Clone;
 }
 
 srml_support::decl_module! {
@@ -41,6 +41,9 @@ srml_support::decl_storage!{
 
 		pub DoubleMap: double_map u32, blake2_256(u32) => u32;
 		pub DoubleMap2: double_map hasher(twox_128) u32, blake2_128(u32) => u32;
+
+		pub Foo get(foo) config(): Option<T::BlockNumber>;
+		pub Foo2 get(foo2) config(): double_map u32, blake2_256(T::BlockNumber) => Option<u32>;
 	}
 }