diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5150bb0c09f..2e37d4b227a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@
     - NodeJS:
       - CHANGED: Use node-api instead of NAN. [#6452](https://github.com/Project-OSRM/osrm-backend/pull/6452)
     - Misc:
+      - FIXED: Fix an error in a RouteParameters AnnotationsType operator overload. [#6646](https://github.com/Project-OSRM/osrm-backend/pull/6646)
       - ADDED: Add support for "unlimited" to be passed as a value for the default-radius and max-matching-radius flags. [#6599](https://github.com/Project-OSRM/osrm-backend/pull/6599)
       - CHANGED: Allow -1.0 as unlimited for default_radius value. [#6599](https://github.com/Project-OSRM/osrm-backend/pull/6599)
       - CHANGED: keep libosrm* in the docker image for downstream linking [#6602](https://github.com/Project-OSRM/osrm-backend/pull/6602)
diff --git a/include/engine/api/route_parameters.hpp b/include/engine/api/route_parameters.hpp
index fe121a06d1a..3593ecf5ba5 100644
--- a/include/engine/api/route_parameters.hpp
+++ b/include/engine/api/route_parameters.hpp
@@ -202,8 +202,8 @@ inline RouteParameters::AnnotationsType operator|(RouteParameters::AnnotationsTy
         static_cast<std::underlying_type_t<RouteParameters::AnnotationsType>>(rhs));
 }
 
-inline RouteParameters::AnnotationsType operator|=(RouteParameters::AnnotationsType lhs,
-                                                   RouteParameters::AnnotationsType rhs)
+inline RouteParameters::AnnotationsType &operator|=(RouteParameters::AnnotationsType &lhs,
+                                                    RouteParameters::AnnotationsType rhs)
 {
     return lhs = lhs | rhs;
 }
diff --git a/package-lock.json b/package-lock.json
index 457213005a9..e235c096fb8 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2220,9 +2220,9 @@
       }
     },
     "node_modules/@mapbox/node-pre-gyp/node_modules/make-dir/node_modules/semver": {
-      "version": "6.3.0",
-      "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.0.tgz",
-      "integrity": "sha512-b39TBaTSfV6yBrapU89p5fKekE2m/NwnDocOVruQFS1/veMgdzuPcnOM34M6CwxW8jH/lxEa5rBoDeUwu5HHTw==",
+      "version": "6.3.1",
+      "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.1.tgz",
+      "integrity": "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA==",
       "bin": {
         "semver": "bin/semver.js"
       }
@@ -2253,9 +2253,9 @@
       }
     },
     "node_modules/@mapbox/node-pre-gyp/node_modules/semver": {
-      "version": "7.3.7",
-      "resolved": "https://registry.npmjs.org/semver/-/semver-7.3.7.tgz",
-      "integrity": "sha512-QlYTucUYOews+WeEujDoEGziz4K6c47V/Bd+LjSSYcA94p+DmINdf7ncaUinThfvZyu13lN9OY1XDxt8C0Tw0g==",
+      "version": "7.5.4",
+      "resolved": "https://registry.npmjs.org/semver/-/semver-7.5.4.tgz",
+      "integrity": "sha512-1bCSESV6Pv+i21Hvpxp3Dx+pSD8lIPt8uVjRrxAUt/nbswYc+tK6Y2btiULjd4+fnq15PX+nqQDC7Oft7WkwcA==",
       "dependencies": {
         "lru-cache": "^6.0.0"
       },
@@ -20422,9 +20422,9 @@
           },
           "dependencies": {
             "semver": {
-              "version": "6.3.0",
-              "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.0.tgz",
-              "integrity": "sha512-b39TBaTSfV6yBrapU89p5fKekE2m/NwnDocOVruQFS1/veMgdzuPcnOM34M6CwxW8jH/lxEa5rBoDeUwu5HHTw=="
+              "version": "6.3.1",
+              "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.1.tgz",
+              "integrity": "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA=="
             }
           }
         },
@@ -20445,9 +20445,9 @@
           }
         },
         "semver": {
-          "version": "7.3.7",
-          "resolved": "https://registry.npmjs.org/semver/-/semver-7.3.7.tgz",
-          "integrity": "sha512-QlYTucUYOews+WeEujDoEGziz4K6c47V/Bd+LjSSYcA94p+DmINdf7ncaUinThfvZyu13lN9OY1XDxt8C0Tw0g==",
+          "version": "7.5.4",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-7.5.4.tgz",
+          "integrity": "sha512-1bCSESV6Pv+i21Hvpxp3Dx+pSD8lIPt8uVjRrxAUt/nbswYc+tK6Y2btiULjd4+fnq15PX+nqQDC7Oft7WkwcA==",
           "requires": {
             "lru-cache": "^6.0.0"
           }