diff --git a/src/freedreno/ir3/ir3_lexer.l b/src/freedreno/ir3/ir3_lexer.l
index 542e6ee6efa..2aef2f52a52 100644
--- a/src/freedreno/ir3/ir3_lexer.l
+++ b/src/freedreno/ir3/ir3_lexer.l
@@ -152,6 +152,7 @@ static int parse_reg(const char *str)
 "@tex"                            return TOKEN(T_A_TEX);
 "@pvtmem"                         return TOKEN(T_A_PVTMEM);
 "@localmem"                       return TOKEN(T_A_LOCALMEM);
+"@constlen"                       return TOKEN(T_A_CONSTLEN);
 "@earlypreamble"                  return TOKEN(T_A_EARLYPREAMBLE);
 "@fullnopstart"                   return TOKEN(T_A_FULLNOPSTART);
 "@fullnopend"                     return TOKEN(T_A_FULLNOPEND);
diff --git a/src/freedreno/ir3/ir3_parser.y b/src/freedreno/ir3/ir3_parser.y
index 4ea38e0d7dd..3ee917d9986 100644
--- a/src/freedreno/ir3/ir3_parser.y
+++ b/src/freedreno/ir3/ir3_parser.y
@@ -82,6 +82,7 @@ static void print_token(FILE *file, int type, YYSTYPE value)
 %token <tok> T_A_TEX
 %token <tok> T_A_PVTMEM
 %token <tok> T_A_LOCALMEM
+%token <tok> T_A_CONSTLEN
 %token <tok> T_A_EARLYPREAMBLE
 %token <tok> T_A_FULLNOPSTART
 %token <tok> T_A_FULLNOPEND
@@ -508,6 +509,7 @@ header:            localsize_header
 |                  pvtmem_header
 |                  localmem_header
 |                  earlypreamble_header
+|                  constlen_header
 
 const_val:         T_FLOAT   { $$ = fui($1); }
 |                  T_INT     { $$ = $1;      }
@@ -587,6 +589,8 @@ localmem_header: T_A_LOCALMEM const_val { variant->shared_size = $2; }
 
 earlypreamble_header: T_A_EARLYPREAMBLE { variant->early_preamble = 1; }
 
+constlen_header: T_A_CONSTLEN const_val { variant->constlen = $2; }
+
 /* Stubs for now */
 in_header:         T_A_IN '(' T_REGISTER ')' T_IDENTIFIER '(' T_IDENTIFIER '=' integer ')' { }