diff --git a/include/momo/details/HashBucketOpen2N2.h b/include/momo/details/HashBucketOpen2N2.h
index 2ff0d7c2..20e7c695 100644
--- a/include/momo/details/HashBucketOpen2N2.h
+++ b/include/momo/details/HashBucketOpen2N2.h
@@ -47,28 +47,25 @@ namespace internal
 		typedef BucketParamsOpen<MemManager> Params;
 
 	private:
-		template<size_t count, bool useHashCodePartGetter>
-		struct HashData;
+		typedef typename UIntSelector<useHashCodePartGetter ? 1 : 2>::UInt ShortHash;
 
-		template<size_t count>
-		struct HashData<count, false>
+		template<size_t codeCount = maxCount, bool hasCodeProbes = useHashCodePartGetter>
+		struct HashData
 		{
-			union
-			{
-				uint16_t shortHashes[count];
-				uint8_t hashProbes[count];
-			};
+			ShortHash shortHashes[codeCount];
+			uint8_t hashProbes[codeCount];
 		};
 
-		template<size_t count>
-		struct HashData<count, true>
+		template<size_t codeCount>
+		struct HashData<codeCount, false>
 		{
-			uint8_t shortHashes[count];
-			uint8_t hashProbes[count];
+			union
+			{
+				ShortHash shortHashes[codeCount];
+				uint8_t hashProbes[codeCount];
+			};
 		};
 
-		typedef typename UIntSelector<useHashCodePartGetter ? 1 : 2>::UInt ShortHash;
-
 		static const size_t hashCodeShift = sizeof(size_t) * 8 - sizeof(ShortHash) * 8 + 1;
 		static const ShortHash emptyShortHash = ShortHash{1} << (sizeof(ShortHash) * 8 - 1);
 		static const uint8_t emptyHashProbe = 255;
@@ -257,7 +254,7 @@ namespace internal
 
 	private:
 		uint8_t mState[2];
-		HashData<maxCount, useHashCodePartGetter> mHashData;
+		HashData<> mHashData;
 		ObjectBuffer<Item, ItemTraits::alignment, maxCount> mItems;
 	};
 }
diff --git a/include/momo/details/TreeNode.h b/include/momo/details/TreeNode.h
index 52e32a86..2007d3f9 100644
--- a/include/momo/details/TreeNode.h
+++ b/include/momo/details/TreeNode.h
@@ -46,20 +46,17 @@ namespace internal
 	private:
 		typedef BoolConstant<isContinuous> IsContinuous;
 
-		template<size_t capacity, bool hasIndexes>
-		struct Counter;
-
-		template<size_t capacity>
-		struct Counter<capacity, false>
+		template<size_t capacity = maxCapacity, size_t indexCount = isContinuous ? 0 : capacity>
+		struct Counter
 		{
 			uint8_t count;
+			uint8_t indexes[indexCount];
 		};
 
 		template<size_t capacity>
-		struct Counter<capacity, true>
+		struct Counter<capacity, 0>
 		{
 			uint8_t count;
-			uint8_t indexes[capacity];
 		};
 
 		typedef internal::MemManagerPtr<MemManager> MemManagerPtr;