diff --git a/katapult/plugins/catalogs/calculatorcatalog/parser.cpp b/katapult/plugins/catalogs/calculatorcatalog/parser.cpp
index 390785e..81f1b6f 100644
--- a/katapult/plugins/catalogs/calculatorcatalog/parser.cpp
+++ b/katapult/plugins/catalogs/calculatorcatalog/parser.cpp
@@ -183,7 +183,7 @@ union yyalloc
 #   define YYCOPY(To, From, Count)		\
       do					\
 	{					\
-	  register YYSIZE_T yyi;		\
+	  YYSIZE_T yyi;		\
 	  for (yyi = 0; yyi < (Count); yyi++)	\
 	    (To)[yyi] = (From)[yyi];		\
 	}					\
@@ -625,7 +625,7 @@ yystrlen (yystr)
      const char *yystr;
 #   endif
 {
-  register const char *yys = yystr;
+  const char *yys = yystr;
 
   while (*yys++ != '\0')
     continue;
@@ -650,8 +650,8 @@ yystpcpy (yydest, yysrc)
      const char *yysrc;
 #   endif
 {
-  register char *yyd = yydest;
-  register const char *yys = yysrc;
+  char *yyd = yydest;
+  const char *yys = yysrc;
 
   while ((*yyd++ = *yys++) != '\0')
     continue;
@@ -786,8 +786,8 @@ YYSTYPE yylval;
 /* Number of syntax errors so far.  */
 int yynerrs;
 
-  register int yystate;
-  register int yyn;
+  int yystate;
+  int yyn;
   int yyresult;
   /* Number of tokens to shift before error messages enabled.  */
   int yyerrstatus;
@@ -805,12 +805,12 @@ int yynerrs;
   /* The state stack.  */
   short int yyssa[YYINITDEPTH];
   short int *yyss = yyssa;
-  register short int *yyssp;
+  short int *yyssp;
 
   /* The semantic value stack.  */
   YYSTYPE yyvsa[YYINITDEPTH];
   YYSTYPE *yyvs = yyvsa;
-  register YYSTYPE *yyvsp;
+  YYSTYPE *yyvsp;