diff --git a/common/format-output.c b/common/format-output.c
index c6ab3bf4..c7e021b5 100644
--- a/common/format-output.c
+++ b/common/format-output.c
@@ -40,6 +40,48 @@ static void print_uuid(const u8 *uuid)
 	}
 }
 
+static void print_escaped(const char *str)
+{
+	while (*str) {
+		switch (*str) {
+		case '\b':			/* 0x08 */
+			putchar('\\');
+			putchar('b');
+			break;
+		case '\t':			/* 0x09 */
+			putchar('\\');
+			putchar('t');
+			break;
+		case '\n':			/* 0x0a */
+			putchar('\\');
+			putchar('n');
+			break;
+		case '\f':			/* 0x0c */
+			putchar('\\');
+			putchar('f');
+			break;
+		case '\r':			/* 0x0d */
+			putchar('\\');
+			putchar('r');
+			break;
+		/* Other control characters from 0 .. 31 */
+		case '\v':			/* 0x0b */
+		case 0x00 ... 0x07:
+		case 0x0e ... 0x1f:
+			printf("\\u%04x", *str);
+			break;
+		/* '/' (solidus) not escaped */
+		case '"':
+		case '\\':
+			putchar('\\');
+			/* fallthrough */
+		default:
+			putchar(*str);
+		}
+		str++;
+	}
+}
+
 static void fmt_indent1(int indent)
 {
 	while (indent--)
@@ -281,6 +323,10 @@ void fmt_print(struct format_ctx *fctx, const char* key, ...)
 
 	if (row->fmt[0] == '%') {
 		vprintf(row->fmt, args);
+	} else if (strcmp(row->fmt, "str") == 0) {
+		const char *str = va_arg(args, const char *);
+
+		print_escaped(str);
 	} else if (strcmp(row->fmt, "uuid") == 0) {
 		const u8 *uuid = va_arg(args, const u8*);
 
diff --git a/tests/json-formatter-test.c b/tests/json-formatter-test.c
index c9289864..cfe47709 100644
--- a/tests/json-formatter-test.c
+++ b/tests/json-formatter-test.c
@@ -66,12 +66,38 @@ void test1()
 	fmt_end(&fctx);
 }
 
+/* Escaped strings */
+void test2_escape()
+{
+	static const struct rowspec rows1[] = {
+		{ .key = "devid", .fmt = "%llu", .out_text = "devid", .out_json = "devid" },
+		{ .key = "path1", .fmt = "str", .out_text = "path1", .out_json = "path1" },
+		{ .key = "path2", .fmt = "str", .out_text = "path2", .out_json = "path2" },
+		ROWSPEC_END
+	};
+	struct format_ctx fctx;
+	char control_chars[] = { [0] = '.', [0x20] = 0 };
+	int i;
+
+	for (i = 1; i < 0x20; i++)
+		control_chars[i] = i;
+
+	fmt_start(&fctx, rows1, 32, 0);
+	fmt_print_start_group(&fctx, "device-info", JSON_TYPE_MAP);
+	fmt_print(&fctx, "devid", 1);
+	fmt_print(&fctx, "path1", "/fun\ny/p\th/\b/\\/\f\"quo\rte\"");
+	fmt_print(&fctx, "path2", control_chars);
+	fmt_print_end_group(&fctx, NULL);
+	fmt_end(&fctx);
+}
+
 int main(int argc, char **argv)
 {
 	int testno;
 	static void (*tests[])() = {
 		test_simple_empty,
 		test1,
+		test2_escape,
 	};
 
 	btrfs_config_init();