diff --git a/devguide/wallets.rst b/devguide/wallets.rst
index 273deeb1..7aef1176 100644
--- a/devguide/wallets.rst
+++ b/devguide/wallets.rst
@@ -127,7 +127,7 @@ Private Key Formats
 
 Private keys are what are used to unlock satoshis from a particular address. In Bitcoin, a private key in standard format is simply a 256-bit number, between the values:
 
-0x01 and 0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140, representing nearly the entire range of 2256-1 values. The range is governed by the `secp256k1 <http://www.secg.org/sec2-v2.pdf>`__ `ECDSA <https://en.wikipedia.org/wiki/Elliptic_Curve_DSA>`__ encryption standard used by Bitcoin.
+0x01 and 0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140, representing nearly the entire range of 2 :sup:`256` -1 values. The range is governed by the `secp256k1 <http://www.secg.org/sec2-v2.pdf>`__ `ECDSA <https://en.wikipedia.org/wiki/Elliptic_Curve_DSA>`__ encryption standard used by Bitcoin.
 
 Wallet Import Format (WIF)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^