diff --git a/matter/matter/builder.py b/matter/matter/builder.py
index 133e62c07..a4327fab3 100644
--- a/matter/matter/builder.py
+++ b/matter/matter/builder.py
@@ -85,6 +85,7 @@ class PackageBuilder(object):
 
         self._missing_use_packages = {}
         self._needed_unstable_keywords = set()
+        self._needed_package_mask_changes = set()
 
     @classmethod
     def _build_standard_environment(cls, repository=None):
@@ -178,6 +179,13 @@ class PackageBuilder(object):
         """
         return self._needed_unstable_keywords
 
+    def get_needed_package_mask_changes(self):
+        """
+        Return the list of packages that haven't been merged due to the need
+        of package.mask changes.
+        """
+        return self._needed_package_mask_changes
+
     def run(self):
         """
         Execute Package building action.
@@ -726,6 +734,10 @@ class PackageBuilder(object):
                     for pkg in v:
                         self._needed_unstable_keywords.add(
                             copy.deepcopy(pkg.cpv))
+                elif k == "needed_p_mask_changes":
+                    for pkg in v:
+                        self._needed_package_mask_changes.add(
+                            copy.deepcopy(pkg.cpv))
                 else:
                     print_warning("unsupported backtrack info: %s -> %s" % (
                             k, v,))
diff --git a/matter/matter/main.py b/matter/matter/main.py
index 468b51c3a..17f94cc9e 100644
--- a/matter/matter/main.py
+++ b/matter/matter/main.py
@@ -87,6 +87,7 @@ def matter_main(binary_pms, nsargs, cwd, specs):
     uninstalled = []
     missing_use = {}
     unstable_keywords = set()
+    pmask_changes = set()
     tainted_repositories = set()
     spec_count = 0
     tot_spec = len(specs)
@@ -119,6 +120,8 @@ def matter_main(binary_pms, nsargs, cwd, specs):
                 builder.get_missing_use_packages())
             unstable_keywords.update(
                 builder.get_needed_unstable_keywords())
+            pmask_changes.update(
+                builder.get_needed_package_mask_changes())
             preserved_libs = binary_pms.check_preserved_libraries(
                 emerge_config)
 
@@ -208,12 +211,19 @@ def matter_main(binary_pms, nsargs, cwd, specs):
             print_generic("%s %s" % (
                     use_data["cp:slot"], " ".join(use_l)))
         print_generic("")
+
     if unstable_keywords:
         print_generic("Packages not built due to missing unstable keywords:")
         for atom in sorted(unstable_keywords):
             print_generic("%s" % (atom,))
         print_generic("")
 
+    if pmask_changes:
+        print_generic("Packages not built due to needed package.mask changes:")
+        for atom in sorted(pmask_changes):
+            print_generic("%s" % (atom,))
+        print_generic("")
+
     print_generic("Preserved libs: %s" % (
         preserved_libs,))
     print_generic("")