diff --git a/src/parse-gram.c b/src/parse-gram.c
index 11328b63..aab9ef69 100644
--- a/src/parse-gram.c
+++ b/src/parse-gram.c
@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.8.3-84b7.  */
+/* A Bison parser, made by GNU Bison 3.8.1.  */
 
 /* Bison implementation for Yacc-like parsers in C
 
@@ -46,10 +46,10 @@
    USER NAME SPACE" below.  */
 
 /* Identify Bison output, and Bison version.  */
-#define YYBISON -1
+#define YYBISON 30801
 
 /* Bison version string.  */
-#define YYBISON_VERSION "3.8.3-84b7"
+#define YYBISON_VERSION "3.8.1"
 
 /* Skeleton name.  */
 #define YYSKELETON_NAME "yacc.c"
diff --git a/src/parse-gram.h b/src/parse-gram.h
index 37c62e22..55837bc4 100644
--- a/src/parse-gram.h
+++ b/src/parse-gram.h
@@ -1,4 +1,4 @@
-/* A Bison parser, made by GNU Bison 3.8.3-84b7.  */
+/* A Bison parser, made by GNU Bison 3.8.1.  */
 
 /* Bison interface for Yacc-like parsers in C