diff --git a/compiler/lib/Support/KeySet.cpp b/compiler/lib/Support/KeySet.cpp
index dee58f6f0..375e9db71 100644
--- a/compiler/lib/Support/KeySet.cpp
+++ b/compiler/lib/Support/KeySet.cpp
@@ -267,11 +267,10 @@ llvm::Error KeySet::decrypt_lwe(size_t argPos, LweCiphertext_u64 *ciphertext,
       decrypt_lwe_u64(&err, std::get<2>(outputSk), ciphertext, &plaintext),
       "cannot decrypt");
   // Decode
-  double divisor = std::pow(
-      2, 64 - (std::get<0>(outputSk).encryption->encoding.precision + 1));
-  output = std::round(((double)plaintext._0) / divisor);
-  output %= (1 << (std::get<0>(outputSk).encryption->encoding.precision + 1));
-
+  size_t precision = std::get<0>(outputSk).encryption->encoding.precision;
+  output = plaintext._0 >> (64 - precision - 2);
+  size_t carry = output % 2;
+  output = ((output >> 1) + carry) % (1 << (precision + 1));
   return llvm::Error::success();
 }