diff --git a/web/client/codechecker_client/helpers/base.py b/web/client/codechecker_client/helpers/base.py
index 7429fa92ec..3c51da9df3 100644
--- a/web/client/codechecker_client/helpers/base.py
+++ b/web/client/codechecker_client/helpers/base.py
@@ -9,13 +9,17 @@
 Base Helper class for Thrift api calls.
 """
 
-
+import sys
 from thrift.transport import THttpClient
 from thrift.protocol import TJSONProtocol
 
 from codechecker_client.credential_manager import SESSION_COOKIE_NAME
 from codechecker_client.product import create_product_url
 
+from codechecker_common.logger import get_logger
+
+LOG = get_logger('system')
+
 
 class BaseClientHelper(object):
 
@@ -28,13 +32,43 @@ def __init__(self, protocol, host, port, uri, session_token=None,
         self.__port = port
         url = create_product_url(protocol, host, port, uri)
 
-        self.transport = THttpClient.THttpClient(url)
+        self.transport = None
+
+        try:
+            self.transport = THttpClient.THttpClient(url)
+        except ValueError:
+            # Initalizing THttpClient may raise an exception if proxy settings
+            # are used but the port number is not a valid integer.
+            pass
+        finally:
+            # Thrift do not handle the use case when invalid proxy format is
+            # used (e.g.: no schema is specified). For this reason we need to
+            # verify the proxy format in our side.
+            self._validate_proxy_format()
+
         self.protocol = TJSONProtocol.TJSONProtocol(self.transport)
         self.client = None
 
         self.get_new_token = get_new_token
         self._set_token(session_token)
 
+    def _validate_proxy_format(self):
+        """
+        Validate the proxy settings.
+        If the proxy settings are invalid, it will print an error message and
+        stop the program.
+        """
+        if self.transport and not self.transport.using_proxy():
+            return
+
+        if not self.transport or not self.transport.host or \
+                not isinstance(self.transport.port, int):
+            LOG.error("Invalid proxy format! Check your "
+                      "HTTP_PROXY/HTTPS_PROXY environment variables if "
+                      "these are in the right format: "
+                      "'http[s]://host:port'.")
+            sys.exit(1)
+
     def _set_token(self, session_token):
         """ Set the given token in the transport layer. """
         if not session_token:
diff --git a/web/client/codechecker_client/thrift_call.py b/web/client/codechecker_client/thrift_call.py
index 82bf99753f..800c74ca86 100644
--- a/web/client/codechecker_client/thrift_call.py
+++ b/web/client/codechecker_client/thrift_call.py
@@ -21,37 +21,6 @@
 
 LOG = get_logger('system')
 
-PROXY_VALIDATION_NEEDED = True
-
-
-def proxy_settings_are_valid(transport):
-    """
-    Return True if no proxy settings are used or the proxy format it valid.
-    """
-    if not transport.using_proxy():
-        return True
-
-    return transport.host and isinstance(transport.port, int)
-
-
-def validate_proxy_format(transport):
-    """
-    It will check the proxy settings once and validate the proxy settings.
-    If the proxy settings are invalid, it will print an error message and
-    stop the program.
-    """
-    global PROXY_VALIDATION_NEEDED
-
-    if PROXY_VALIDATION_NEEDED:
-        if not proxy_settings_are_valid(transport):
-            LOG.error("Invalid proxy format! Check your "
-                      "HTTP_PROXY/HTTPS_PROXY environment variables if "
-                      "these are in the right format:"
-                      "'http[s]://host:port'.")
-            sys.exit(1)
-
-        PROXY_VALIDATION_NEEDED = False
-
 
 def truncate_arg(arg, max_len=100):
     """ Truncate the given argument if the length is too large. """
@@ -69,11 +38,6 @@ def ThriftClientCall(function):
     funcName = function.__name__
 
     def wrapper(self, *args, **kwargs):
-        # Thrift do not handle the use case when invalid proxy format is used
-        # (e.g.: no schema is specified). For this reason we need to verify
-        # the proxy format in our side.
-        validate_proxy_format(self.transport)
-
         self.transport.open()
         func = getattr(self.client, funcName)
         try: