diff --git a/usr.bin/indent/lexi.c b/usr.bin/indent/lexi.c
index b9ff1de94dcf..6deb55ae6853 100644
--- a/usr.bin/indent/lexi.c
+++ b/usr.bin/indent/lexi.c
@@ -169,19 +169,47 @@ lexi(void)
 	struct templ *p;
 
 	if (isdigit(*buf_ptr) || (buf_ptr[0] == '.' && isdigit(buf_ptr[1]))) {
+	    enum base {
+		BASE_2, BASE_8, BASE_10, BASE_16
+	    };
 	    int         seendot = 0,
 	                seenexp = 0,
 			seensfx = 0;
-	    if (*buf_ptr == '0' &&
-		    (buf_ptr[1] == 'x' || buf_ptr[1] == 'X')) {
+	    enum base	in_base = BASE_10;
+
+	    if (*buf_ptr == '0') {
+		if (buf_ptr[1] == 'b' || buf_ptr[1] == 'B')
+		    in_base = BASE_2;
+		else if (buf_ptr[1] == 'x' || buf_ptr[1] == 'X')
+		    in_base = BASE_16;
+		else if (isdigit(buf_ptr[1]))
+		    in_base = BASE_8;
+	    }
+	    switch (in_base) {
+	    case BASE_2:
+		*e_token++ = *buf_ptr++;
+		*e_token++ = *buf_ptr++;
+		while (*buf_ptr == '0' || *buf_ptr == '1') {
+		    CHECK_SIZE_TOKEN;
+		    *e_token++ = *buf_ptr++;
+		}
+		break;
+	    case BASE_8:
+		*e_token++ = *buf_ptr++;
+		while (*buf_ptr >= '0' && *buf_ptr <= '8') {
+		    CHECK_SIZE_TOKEN;
+		    *e_token++ = *buf_ptr++;
+		}
+		break;
+	    case BASE_16:
 		*e_token++ = *buf_ptr++;
 		*e_token++ = *buf_ptr++;
 		while (isxdigit(*buf_ptr)) {
 		    CHECK_SIZE_TOKEN;
 		    *e_token++ = *buf_ptr++;
 		}
-	    }
-	    else
+		break;
+	    case BASE_10:
 		while (1) {
 		    if (*buf_ptr == '.') {
 			if (seendot)
@@ -204,6 +232,8 @@ lexi(void)
 			}
 		    }
 		}
+		break;
+	    }
 	    while (1) {
 		if (!(seensfx & 1) && (*buf_ptr == 'U' || *buf_ptr == 'u')) {
 		    CHECK_SIZE_TOKEN;
diff --git a/usr.bin/indent/tests/Makefile b/usr.bin/indent/tests/Makefile
index 1b6abb835828..01fa04aca755 100644
--- a/usr.bin/indent/tests/Makefile
+++ b/usr.bin/indent/tests/Makefile
@@ -2,6 +2,8 @@
 
 PACKAGE=	tests
 
+${PACKAGE}FILES+=	binary.0
+${PACKAGE}FILES+=	binary.0.stdout
 ${PACKAGE}FILES+=	comments.0
 ${PACKAGE}FILES+=	comments.0.stdout
 ${PACKAGE}FILES+=	declarations.0
diff --git a/usr.bin/indent/tests/binary.0 b/usr.bin/indent/tests/binary.0
new file mode 100644
index 000000000000..b2adc1fe6428
--- /dev/null
+++ b/usr.bin/indent/tests/binary.0
@@ -0,0 +1,10 @@
+/* $FreeBSD$ */
+#define b00101010 -1
+void t(void) {
+	unsigned a[] = {0b00101010, 0x00005678, 02, 17U};
+	float x[] = {.7f, 0.7f};
+	unsigned long ul[] = {0b00001111UL, 0x01010101UL, 02UL, 17UL};
+
+	if (0 b00101010)
+		return;
+}
diff --git a/usr.bin/indent/tests/binary.0.stdout b/usr.bin/indent/tests/binary.0.stdout
new file mode 100644
index 000000000000..a883ed9fcd06
--- /dev/null
+++ b/usr.bin/indent/tests/binary.0.stdout
@@ -0,0 +1,12 @@
+/* $FreeBSD$ */
+#define b00101010 -1
+void 
+t(void)
+{
+	unsigned	a[] = {0b00101010, 0x00005678, 02, 17U};
+	float		x[] = {.7f, 0.7f};
+	unsigned long	ul[] = {0b00001111UL, 0x01010101UL, 02UL, 17UL};
+
+	if (0 b00101010)
+		return;
+}