diff --git a/src/chain.cpp b/src/chain.cpp
--- a/src/chain.cpp
+++ b/src/chain.cpp
@@ -141,7 +141,7 @@
     // We need to compute 2**256 / (bnTarget+1), but we can't represent 2**256
     // as it's too large for an arith_uint256. However, as 2**256 is at least as
     // large as bnTarget+1, it is equal to ((2**256 - bnTarget - 1) /
-    // (bnTarget+1)) + 1, or ~bnTarget / (nTarget+1) + 1.
+    // (bnTarget+1)) + 1, or ~bnTarget / (bnTarget+1) + 1.
     return (~bnTarget / (bnTarget + 1)) + 1;
 }