diff --git a/Compiler/ml.py b/Compiler/ml.py
index a1f1c4dc..30059d5b 100644
--- a/Compiler/ml.py
+++ b/Compiler/ml.py
@@ -885,7 +885,10 @@ class Dense(DenseBase):
 
     def compute_f_input(self, batch):
         N = len(batch)
-        prod = MultiArray([N, self.d, self.d_out], sfix)
+        if self.input_bias:
+            prod = MultiArray([N, self.d, self.d_out], sfix)
+        else:
+            prod = self.f_input
 
         # flattened_array version
         result_matrix = sfix.Matrix(N * self.d, self.d_out, address=prod.address)