diff --git a/lldb/test/API/commands/register/register/TestRegistersUnavailable.py b/lldb/test/API/commands/register/register/TestRegistersUnavailable.py
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/commands/register/register/TestRegistersUnavailable.py
@@ -0,0 +1,57 @@
+""" Check that unavailable registers are reported when reading register sets."""
+
+from textwrap import dedent
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+from lldbsuite.test.gdbclientutils import *
+from lldbsuite.test.lldbgdbclient import GDBRemoteTestBase
+
+class MyResponder(MockGDBServerResponder):
+    def readRegisters(self):
+        return "E01"
+
+    def readRegister(self, regnum):
+        # Only allow reads of rip.
+        if regnum in [0, 1, 2]:
+            return "E01"
+        return "5555555555555555"
+
+    def qXferRead(self, obj, annex, offset, length):
+        if annex == "target.xml":
+            return """<?xml version="1.0"?>
+                <target version="1.0">
+                  <architecture>i386:x86-64</architecture>
+                  <feature name="org.gnu.gdb.i386.core">
+                    <reg name="rax" bitsize="64" regnum="0" group="general"/>
+                    <reg name="rbx" bitsize="64" regnum="1" group="general"/>
+                    <reg name="rsi" bitsize="64" regnum="2" group="other"/>
+                    <reg name="rip" bitsize="64" regnum="3" group="general" generic="pc"/>
+                  </feature>
+                </target>""", False
+        else:
+            return None, False
+
+class TestRegistersUnavailable(GDBRemoteTestBase):
+    @skipIfXmlSupportMissing
+    @skipIfRemote
+    def test_unavailable_registers(self):
+        self.server.responder = MyResponder()
+        target = self.dbg.CreateTarget('')
+
+        if self.TraceOn():
+            self.runCmd("log enable gdb-remote packets process")
+            self.addTearDownHook(
+                lambda: self.runCmd("log disable gdb-remote packets process"))
+
+        process = self.connect(target)
+        lldbutil.expect_state_changes(self, self.dbg.GetListener(), process,
+                                      [lldb.eStateStopped])
+
+        self.expect("register read --all", substrs=[
+            "general:\n"
+            "       rip = 0x5555555555555555\n"
+            "2 registers were unavailable.\n"
+            "\n"
+            "other:\n"
+            "1 registers were unavailable."])