diff --git a/src/core/peg.c b/src/core/peg.c
index a814e65f..a087ddfa 100644
--- a/src/core/peg.c
+++ b/src/core/peg.c
@@ -735,6 +735,12 @@ static const uint8_t *peg_getrange(Builder *b, Janet x) {
     return str;
 }
 
+static int32_t peg_getboolean(Builder *b, Janet x) {
+	if (!janet_checktype(x, JANET_BOOLEAN))
+		peg_panicf(b, "expected boolean, got %v", x);
+	return janet_unwrap_boolean(x);
+}
+
 static int32_t peg_getinteger(Builder *b, Janet x) {
     if (!janet_checkint(x))
         peg_panicf(b, "expected integer, got %v", x);
@@ -1261,6 +1267,13 @@ static uint32_t peg_compile1(Builder *b, Janet peg) {
         default:
             peg_panic(b, "unexpected peg source");
             return 0;
+
+		case JANET_BOOLEAN: {
+			int n = peg_getboolean(b, peg);
+			Reserve r = reserve(b, 2);
+			emit_1(r, n ? RULE_NCHAR : RULE_NOTNCHAR, 0);
+			break;
+		}
         case JANET_NUMBER: {
             int32_t n = peg_getinteger(b, peg);
             Reserve r = reserve(b, 2);