diff --git a/text/neqn/lex.c b/text/neqn/lex.c
index 1d9afe9..1e1d241 100644
--- a/text/neqn/lex.c
+++ b/text/neqn/lex.c
@@ -4,9 +4,11 @@
 #include "e.h"
 #include "y.tab.h"
 
+extern YYSTYPE yyval;
+
 #define	SSIZE	400
 char	token[SSIZE];
-int	sp, yyval;
+int	sp;
 #define	putbak(c)	*ip++ = c;
 #define	PUSHBACK	300	/* maximum pushback characters */
 char	ibuf[PUSHBACK+SSIZE];	/* pushback buffer for definitions, etc. */
@@ -212,7 +214,7 @@ include() {
 }
 
 delim() {
-	yyval = eqnreg = 0;
+	yyval.token = eqnreg = 0;
 	if (cstr(token, 0, SSIZE))
 		error(FATAL, "Bizarre delimiters at %.20s", token);
 	lefteq = token[0];
diff --git a/text/neqn/neqn.mk b/text/neqn/neqn.mk
index 0bb5b8a..e510e16 100644
--- a/text/neqn/neqn.mk
+++ b/text/neqn/neqn.mk
@@ -51,7 +51,7 @@ install : all
 	@chown $(OWNER) $(MAN1DIR)/neqn.1
 
 clean :
-	rm -f *.o y.tab.c y.tab.h
+	rm -f *.o y.tab.c y.tab.h e.c
 
 clobber : clean
 	rm -f neqn
@@ -61,6 +61,10 @@ neqn : $(OFILES)
 
 $(OFILES) : e.h e.o
 
+e.c: e.y
+	$(YACC) -d e.y
+	sed -f yyval.sed <y.tab.c >$@
+
 changes :
 	@trap "" 1 2 3 15; \
 	sed \
diff --git a/text/neqn/yyval.sed b/text/neqn/yyval.sed
new file mode 100644
index 0000000..fbbc5e8
--- /dev/null
+++ b/text/neqn/yyval.sed
@@ -0,0 +1,22 @@
+#
+# Sccsid @(#)yyval.sed	1.2 (gritter) 10/2/07
+#
+# bison has a yacc-compatible yyval, but it is a local variable inside
+# yyparse(). Making the variable global is necessary to make bc work
+# with a bison-generated parser.
+1,2 {
+	/Bison/ {
+	:look
+		/second part of user declarations/ {
+			i\
+			YYSTYPE yyval;
+		:repl
+			s/^[ 	]*YYSTYPE[ 	]*yyval;//
+			n
+			t
+			b repl
+		}
+		n
+		b look
+	}
+}