diff --git a/reference/nim/proof_input/proof_input.nimble b/reference/nim/proof_input/proof_input.nimble
index 263f639..794179e 100644
--- a/reference/nim/proof_input/proof_input.nimble
+++ b/reference/nim/proof_input/proof_input.nimble
@@ -8,4 +8,4 @@ bin           = @["cli","testmain"]
 
 requires "nim >= 1.6.0"
 requires "https://github.com/mratsim/constantine"
-requires "https://github.com/codex-storage/nim-poseidon2#596f7b18070b44ca0bf305bf9bdf1dc4f6011181"
+requires "https://github.com/codex-storage/nim-poseidon2#9be7b0c134e64e3d57a38520a32af93a55a37c44"
diff --git a/reference/nim/proof_input/src/blocks.nim b/reference/nim/proof_input/src/blocks.nim
index 7feb872..7b695cd 100644
--- a/reference/nim/proof_input/src/blocks.nim
+++ b/reference/nim/proof_input/src/blocks.nim
@@ -39,7 +39,7 @@ func splitBlockIntoCells( globcfg: GlobalConfig, blockData: openArray[byte] ): s
 func hashNetworkBlockOpen( globcfg: GlobalConfig, blockData: openArray[byte] ): Hash = 
   let cells  = splitBlockIntoCells(globcfg, blockData)
   let leaves = collect( newSeq , (for i in 0..<cellsPerBlock(globcfg): hashCell(globcfg, cells[i]) ))
-  return merkleRoot(leaves)
+  return Merkle.digest(leaves) # merkleRoot(leaves)
 
 func hashNetworkBlock*(globcfg: GlobalConfig, blockData: Block): Hash = 
   hashNetworkBlockOpen(globcfg, blockData)
diff --git a/reference/nim/proof_input/src/cli.nim b/reference/nim/proof_input/src/cli.nim
index 313ea72..27eb4e2 100644
--- a/reference/nim/proof_input/src/cli.nim
+++ b/reference/nim/proof_input/src/cli.nim
@@ -11,6 +11,7 @@ import constantine/math/arithmetic
 
 import poseidon2/types
 import poseidon2/merkle
+import poseidon2/io
 
 import types
 import blocks
diff --git a/reference/nim/proof_input/src/merkle.nim b/reference/nim/proof_input/src/merkle.nim
index 4914fc7..6dfd6d7 100644
--- a/reference/nim/proof_input/src/merkle.nim
+++ b/reference/nim/proof_input/src/merkle.nim
@@ -7,7 +7,7 @@ import constantine/math/io/io_fields
 
 import poseidon2/types
 import poseidon2/compress
-#import poseidon2/merkle
+import poseidon2/io
 
 import types
 
diff --git a/reference/nim/proof_input/src/sample.nim b/reference/nim/proof_input/src/sample.nim
index 897dd40..ff9b26f 100644
--- a/reference/nim/proof_input/src/sample.nim
+++ b/reference/nim/proof_input/src/sample.nim
@@ -6,7 +6,7 @@ import constantine/math/arithmetic
 
 import poseidon2/types
 import poseidon2/sponge
-#import poseidon2/io
+import poseidon2/io
 
 import types
 import misc