diff --git a/VERSION b/VERSION
index ccbccc3..c043eea 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.0
+2.2.1
diff --git a/containers/chameleon/Dockerfile.chameleon b/containers/chameleon/Dockerfile.chameleon
index 6e326dc..83df7fd 100644
--- a/containers/chameleon/Dockerfile.chameleon
+++ b/containers/chameleon/Dockerfile.chameleon
@@ -14,7 +14,7 @@
 
 # xosproject/chameleon
 
-FROM xosproject/xos-base:2.2.0
+FROM xosproject/xos-base:2.2.1
 
 # xos-base already has protoc and dependencies installed
 
diff --git a/containers/xos/Dockerfile.client b/containers/xos/Dockerfile.client
index 083d01a..8208ec9 100644
--- a/containers/xos/Dockerfile.client
+++ b/containers/xos/Dockerfile.client
@@ -14,7 +14,7 @@
 
 # xosproject/xos-client
 
-FROM xosproject/xos-libraries:2.2.0
+FROM xosproject/xos-libraries:2.2.1
 
 # Install XOS client
 COPY lib/xos-api /tmp/xos-api
diff --git a/containers/xos/Dockerfile.libraries b/containers/xos/Dockerfile.libraries
index 4171077..5a211fa 100644
--- a/containers/xos/Dockerfile.libraries
+++ b/containers/xos/Dockerfile.libraries
@@ -14,7 +14,7 @@
 
 # xosproject/xos-libraries
 
-FROM xosproject/xos-base:2.2.0
+FROM xosproject/xos-base:2.2.1
 
 # Add libraries
 COPY lib /opt/xos/lib
diff --git a/containers/xos/Dockerfile.synchronizer-base b/containers/xos/Dockerfile.synchronizer-base
index 0110aca..ec745c4 100644
--- a/containers/xos/Dockerfile.synchronizer-base
+++ b/containers/xos/Dockerfile.synchronizer-base
@@ -14,7 +14,7 @@
 
 # xosproject/xos-synchronizer-base
 
-FROM xosproject/xos-client:2.2.0
+FROM xosproject/xos-client:2.2.1
 
 COPY xos/synchronizers/new_base /opt/xos/synchronizers/new_base
 COPY xos/xos/logger.py /opt/xos/xos/logger.py
diff --git a/containers/xos/Dockerfile.xos-core b/containers/xos/Dockerfile.xos-core
index 6d024b9..802373b 100644
--- a/containers/xos/Dockerfile.xos-core
+++ b/containers/xos/Dockerfile.xos-core
@@ -14,7 +14,7 @@
 
 # xosproject/xos-core
 
-FROM xosproject/xos-libraries:2.2.0
+FROM xosproject/xos-libraries:2.2.1
 
 # Install XOS
 ADD xos /opt/xos
diff --git a/xos/coreapi/xos_dynamicload_api.py b/xos/coreapi/xos_dynamicload_api.py
index 8a44581..fd46056 100644
--- a/xos/coreapi/xos_dynamicload_api.py
+++ b/xos/coreapi/xos_dynamicload_api.py
@@ -59,21 +59,6 @@
                         django_models[k] = v
                 self.django_app_models[app.name] = django_models
 
-    def match_major_version(self, current, expected):
-        """
-        Returns true if the major version is the same
-        :param current: semver string for the current version
-        :param expected: semver string for the expected version
-        :return: bool
-        """
-        current_parts = semver.parse(current)
-        expected = re.sub("[><=!]", "", expected)
-        expected_parts = semver.parse(expected)
-        match = current_parts["major"] == expected_parts["major"]
-        log.debug("Verifying major version",
-                  expected_major=expected_parts["major"], current_major=current_parts["major"], match=match)
-        return match
-
     @track_request_time("DynamicLoad", "LoadModels")
     def LoadModels(self, request, context):
         try:
@@ -87,28 +72,41 @@
                 )
 
             if not requested_core_version:
-                requested_core_version = "<3.0.0"
+                requested_core_version = ">=2.2.1"
 
-            match_version = semver.match(core_version, requested_core_version)
-            match_major = self.match_major_version(core_version, requested_core_version)
-            if not match_version:
-                log.error("Not loading service because of mismatching versions", service=request.name,
-                          core_version=core_version, requested_core_version=requested_core_version)
-                context.set_code(grpc.StatusCode.INVALID_ARGUMENT)
-                msg = "Service %s is requesting core version %s but actual version is %s" % (
-                request.name, requested_core_version, core_version)
-                context.set_details(msg)
-                raise Exception(msg)
-            if not match_major:
-                log.error("Not loading service because of mismatching major versions", service=request.name,
-                          core_version=core_version, requested_core_version=requested_core_version)
-                context.set_code(grpc.StatusCode.INVALID_ARGUMENT)
-                msg = "Service %s is requesting core version %s but actual version is %s, major version is different" % (
+            if "~" in requested_core_version:
+                [min_requested, max_requested] = requested_core_version.split("~")
+
+                match_min_version = semver.match(core_version, min_requested.strip())
+                match_max_version = semver.match(core_version, max_requested.strip())
+
+                if not match_min_version or not match_max_version:
+                    log.error("Not loading service because of mismatching versions",
+                              service=request.name,
+                              core_version=core_version,
+                              requested_min_core_version=min_requested,
+                              requested_max_core_version=max_requested
+                        )
+                    context.set_code(grpc.StatusCode.INVALID_ARGUMENT)
+                    msg = "Service %s is requesting core version between %s and %s but actual version is %s" % (
+                        request.name,
+                        min_requested,
+                        max_requested,
+                        core_version
+                    )
+                    context.set_details(msg)
+                    raise Exception(msg)
+
+            else:
+                match_version = semver.match(core_version, requested_core_version.strip())
+                if not match_version:
+                    log.error("Not loading service because of mismatching versions", service=request.name,
+                              core_version=core_version, requested_core_version=requested_core_version)
+                    context.set_code(grpc.StatusCode.INVALID_ARGUMENT)
+                    msg = "Service %s is requesting core version %s but actual version is %s" % (
                     request.name, requested_core_version, core_version)
-                context.set_details(msg)
-                raise Exception(msg)
-                context.set_details(msg)
-                raise Exception(msg)
+                    context.set_details(msg)
+                    raise Exception(msg)
 
             builder = DynamicBuilder()
             result = builder.handle_loadmodels_request(request)