diff --git a/Changes b/Changes
index 843fc5ae2..79cbb9fcb 100644
--- a/Changes
+++ b/Changes
@@ -14,6 +14,11 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Fix internals to avoid 'using namespace std'.
 
+****  Fix Verilation performance issues, bug1316. [John Coiner]
+
+
+* Verilator 3.923 devel
+
 ***   Renamed --profile-cfuncs to --prof-cfuncs.
 
 ****  Report interface ports connected to wrong interface, bug1294. [Todd Strader]
@@ -24,7 +29,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Fix parsing error on bad missing #, bug1308. [Dan Kirkham]
 
-****  Fix Verilation performance issues, bug1316. [John Coiner]
+****  Fix $clog2 to be in verilog 2005, bug1319. [James Hutchinson]
+
 
 * Verilator 3.922 2018-03-17
 
diff --git a/src/verilog.l b/src/verilog.l
index f116279a2..0d0ac40b3 100644
--- a/src/verilog.l
+++ b/src/verilog.l
@@ -422,6 +422,8 @@ vnum	{vnum1}|{vnum2}|{vnum3}|{vnum4}|{vnum5}
 
   /* Verilog 2005 */
 <V05,S05,S09,S12,S17,SAX>{
+  /*     System Tasks */
+  "$clog2"		{ FL; return yD_CLOG2; }
   /*     Keywords */
   "uwire"		{ FL; return yWIRE; }
 }
@@ -430,7 +432,6 @@ vnum	{vnum1}|{vnum2}|{vnum3}|{vnum4}|{vnum5}
 <S05,S09,S12,S17,SAX>{
   /*     System Tasks */
   "$bits"		{ FL; return yD_BITS; }
-  "$clog2"		{ FL; return yD_CLOG2; }
   "$countones"		{ FL; return yD_COUNTONES; }
   "$dimensions"		{ FL; return yD_DIMENSIONS; }
   "$error"		{ FL; return yD_ERROR; }