diff --git a/docs/units-and-global-variables.rst b/docs/units-and-global-variables.rst
index 3a12c630a..7fcb2d7ad 100644
--- a/docs/units-and-global-variables.rst
+++ b/docs/units-and-global-variables.rst
@@ -111,7 +111,8 @@ same as ``sha3(uint16(0x12))``.
 
 It might be that you run into Out-of-Gas for ``sha256``, ``ripemd160`` or ``ecrecover`` on a *private blockchain*. The reason for this is that those are implemented as so-called precompiled contracts and these contracts only really exist after they received the first message (although their contract code is hardcoded). Messages to non-existing contracts are more expensive and thus the execution runs into an Out-of-Gas error. A workaround for this problem is to first send e.g. 1 Wei to each of the contracts before you use them in your actual contracts. This is not an issue on the official or test net.
 
-.. index:: send, balance
+.. _balance:
+.. _send:
 
 Address Related
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