diff --git a/src/pending_changes/edg-28967-deep-pointer-qualification.txt b/src/pending_changes/edg-28967-deep-pointer-qualification.txt
new file mode 100644
index 0000000000..f497b1ab30
--- /dev/null
+++ b/src/pending_changes/edg-28967-deep-pointer-qualification.txt
@@ -0,0 +1,5 @@
+[GH #455]
+Reject unsafe deep pointer qualification conversions
+
+GNU C++ mode now rejects pointer qualification conversions that add const
+at a deeper level without adding const at the required intermediate levels.
diff --git a/src/types.c b/src/types.c
index 3e8a3aed1b..4384a9ca85 100644
--- a/src/types.c
+++ b/src/types.c
@@ -11689,6 +11689,7 @@ operators), 3.3.15 (?: operator), and 3.3.16.1 (simple assignment).
           std_conv->warning_suggested = warning_suggested;
           qualifiers_checked = TRUE;
         } else if ((!suppress_extensions || any_cfront_mode()) &&
+                   !gpp_mode &&
                     same_type_with_added_qualifiers(
                            source_type_pointed_to,
                            dest_type_pointed_to,
diff --git a/tests/tests/regressions/edg-28967-positive.sft.cpp b/tests/tests/regressions/edg-28967-positive.sft.cpp
new file mode 100644
index 0000000000..1b29beb7ff
--- /dev/null
+++ b/tests/tests/regressions/edg-28967-positive.sft.cpp
@@ -0,0 +1,9 @@
+//type:fp
+//options_all:--c++20
+//options:--g++ --gnu_version=130300:--strict
+void allow(char **p, char ***q) {
+  char *const *a = p;
+  const char *const *b = p;
+  const char *const *const *c = q;
+  (void)a; (void)b; (void)c;
+}
diff --git a/tests/tests/regressions/edg-28967.sft.cpp b/tests/tests/regressions/edg-28967.sft.cpp
new file mode 100644
index 0000000000..a0b2c939c2
--- /dev/null
+++ b/tests/tests/regressions/edg-28967.sft.cpp
@@ -0,0 +1,9 @@
+//type:fn
+//options_all:--c++20
+//options:--g++ --gnu_version=130300:--g++ --gnu_version=150200:--strict
+void reject(char **p, char ***q) {
+  const char **bad = p;
+  const char ***also_bad = q;
+  (void)bad;
+  (void)also_bad;
+}