diff --git a/argresolver/resolver.py b/argresolver/resolver.py
index <HASH>..<HASH> 100644
--- a/argresolver/resolver.py
+++ b/argresolver/resolver.py
@@ -254,7 +254,8 @@ class EnvironmentResolver(Resolver):
         if prefix is not None:
             lookup = prefix.upper() + '_' + lookup
         newval = os.environ.get(lookup, Missing)
-        if newval is Missing:
-            self.logger.info("Cannot resolve argument '{}' of {}. Try to set environment variable '{}'".format(
+        hasdefault = defaults.get(name, Missing) is not Missing
+        if newval is Missing and not hasdefault:
+            self.logger.warn("Cannot resolve argument '{}' of {}. Try to set environment variable '{}'".format(
                 name, cls, lookup))
         return newval
Supresses logging warning when default is present