Error choosing function signature in ROUND()

[nightly-3.gce.cloudera.com:21000] > select round(1.2345, 2);
Query: select round(1.2345, 2)
+------------------+
| round(1.2345, 2) |
+------------------+
| 1.23             |
+------------------+
Fetched 1 row(s) in 0.12s

[nightly-3.gce.cloudera.com:21000] > select round(1.2345, 2) * pow(10, 10);
Query: select round(1.2345, 2) * pow(10, 10)
ERROR: AnalysisException: null
CAUSED BY: IllegalStateException: Failed analysis after expr substitution.
CAUSED BY: AnalysisException: No matching function with signature: round(DOUBLE, DOUBLE).

[nightly-3.gce.cloudera.com:21000] > select version();
Query: select version()
+----------------------------------------------------------------------------------------------+
| version()                                                                                    |
+----------------------------------------------------------------------------------------------+
| impalad version 2.6.0-cdh5-INTERNAL RELEASE (build 35713197462670a62625b3b36c9af3f24339abc5) |
| Built on Sat, 23 Apr 2016 10:26:03 PST                                                       |
+-------------------------