diff --git a/src/shared/json.c b/src/shared/json.c
index 3ccda282cf..5d3c6aad91 100644
--- a/src/shared/json.c
+++ b/src/shared/json.c
@@ -3462,6 +3462,36 @@ int json_buildv(JsonVariant **ret, va_list ap) {
                         break;
                 }
 
+                case _JSON_BUILD_BASE64: {
+                        const void *p;
+                        size_t n;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        p = va_arg(ap, const void *);
+                        n = va_arg(ap, size_t);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_base64(&add, p, n);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
                 case _JSON_BUILD_OBJECT_BEGIN:
 
                         if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
diff --git a/src/shared/json.h b/src/shared/json.h
index c1999a7411..9bb3e8cd78 100644
--- a/src/shared/json.h
+++ b/src/shared/json.h
@@ -216,6 +216,7 @@ enum {
         _JSON_BUILD_VARIANT,
         _JSON_BUILD_LITERAL,
         _JSON_BUILD_STRV,
+        _JSON_BUILD_BASE64,
         _JSON_BUILD_MAX,
 };
 
@@ -232,6 +233,7 @@ enum {
 #define JSON_BUILD_VARIANT(v) _JSON_BUILD_VARIANT, ({ JsonVariant *_x = v; _x; })
 #define JSON_BUILD_LITERAL(l) _JSON_BUILD_LITERAL, ({ const char *_x = l; _x; })
 #define JSON_BUILD_STRV(l) _JSON_BUILD_STRV, ({ char **_x = l; _x; })
+#define JSON_BUILD_BASE64(p, n) _JSON_BUILD_BASE64, ({ const void *_x = p; _x; }), ({ size_t _y = n; _y; })
 
 int json_build(JsonVariant **ret, ...);
 int json_buildv(JsonVariant **ret, va_list ap);