diff --git a/lldb/test/API/macosx/unregistered-macho/Makefile b/lldb/test/API/macosx/unregistered-macho/Makefile
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/macosx/unregistered-macho/Makefile
@@ -0,0 +1,3 @@
+C_SOURCES = main.c
+
+include Makefile.rules
diff --git a/lldb/test/API/macosx/unregistered-macho/TestUnregisteredMacho.py b/lldb/test/API/macosx/unregistered-macho/TestUnregisteredMacho.py
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/macosx/unregistered-macho/TestUnregisteredMacho.py
@@ -0,0 +1,34 @@
+"""Test that debugserver will parse a mach-o in inferior memory even if it's not loaded."""
+
+import os
+import re
+import subprocess
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+class TestUnregisteredMacho(TestBase):
+
+    # newer debugserver required for jGetLoadedDynamicLibrariesInfos 
+    # to support this
+    @skipIfOutOfTreeDebugserver  
+    @no_debug_info_test
+    @skipUnlessDarwin
+    def test(self):
+        self.build()
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.c"))
+
+        frame = thread.GetFrameAtIndex(0)
+        macho_buf = frame.GetValueForVariablePath("macho_buf")
+        gdb_packet = "process plugin packet send 'jGetLoadedDynamicLibrariesInfos:{\"solib_addresses\":[%d]}]'" % macho_buf.GetValueAsUnsigned() 
+
+        # Send the jGetLoadedDynamicLibrariesInfos packet
+        # to debugserver, asking it to parse the mach-o binary
+        # at this address and give us the UUID etc, even though
+        # dyld doesn't think there is a binary at that address.
+        # We won't get a pathname for the binary (from dyld), but
+        # we will get to the LC_UUID and include that.
+        self.expect (gdb_packet, substrs=['"pathname":""', '"uuid":"1B4E28BA-2FA1-11D2-883F-B9A761BDE3FB"'])
diff --git a/lldb/test/API/macosx/unregistered-macho/main.c b/lldb/test/API/macosx/unregistered-macho/main.c
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/macosx/unregistered-macho/main.c
@@ -0,0 +1,64 @@
+#include <mach/machine.h>
+#include <mach-o/loader.h>
+#include <stdlib.h>
+#include <string.h>
+#include <uuid/uuid.h>
+
+int main ()
+{
+  int size_of_mh_and_cmds = sizeof (struct mach_header_64) + 
+                          sizeof (struct segment_command_64) +
+                          sizeof (struct uuid_command);
+  uint8_t *macho_buf = (uint8_t *) malloc 
+                         (size_of_mh_and_cmds);
+  uint8_t *p = macho_buf;
+  struct mach_header_64 mh;
+  mh.magic = MH_MAGIC_64;
+  mh.cputype = CPU_TYPE_ARM64;
+  mh.cpusubtype = 0;
+  mh.filetype = MH_EXECUTE;
+  mh.ncmds = 2;
+  mh.sizeofcmds = size_of_mh_and_cmds;
+  mh.flags = MH_NOUNDEFS | MH_DYLDLINK | MH_TWOLEVEL | MH_PIE;
+
+  memcpy (p, &mh, sizeof (mh));
+  p += sizeof (mh);
+
+  struct segment_command_64 seg;
+  seg.cmd = LC_SEGMENT_64;
+  seg.cmdsize = sizeof (seg);
+  strcpy (seg.segname, "__TEXT");
+  seg.vmaddr = 0x5000;
+  seg.vmsize = 0x1000;
+  seg.fileoff = 0;
+  seg.filesize = 0;
+  seg.maxprot = 0;
+  seg.initprot = 0;
+  seg.nsects = 0;
+  seg.flags = 0;
+
+  memcpy (p, &seg, sizeof (seg));
+  p += sizeof (seg);
+
+  struct uuid_command uuid;
+  uuid.cmd = LC_UUID;
+  uuid.cmdsize = sizeof (uuid);
+  uuid_clear (uuid.uuid);
+  uuid_parse ("1b4e28ba-2fa1-11d2-883f-b9a761bde3fb", uuid.uuid);
+
+  memcpy (p, &uuid, sizeof (uuid));
+  p += sizeof (uuid);
+
+  // If this needs to be debugged, the memory buffer can be written
+  // to a file with
+  // (lldb) mem rea -b -o /tmp/t -c `p - macho_buf` macho_buf
+  // (lldb) platform shell otool -hlv /tmp/t
+  // to verify that it is well formed.
+
+  // And inside lldb, it should be inspectable via
+  // (lldb) script print(lldb.frame.locals["macho_buf"][0].GetValueAsUnsigned())
+  // 105553162403968
+  // (lldb) process plugin packet send 'jGetLoadedDynamicLibrariesInfos:{"solib_addresses":[105553162403968]}]'
+
+  return 0;  // break here
+}
diff --git a/lldb/tools/debugserver/source/MacOSX/MachProcess.mm b/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
--- a/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
+++ b/lldb/tools/debugserver/source/MacOSX/MachProcess.mm
@@ -1164,6 +1164,8 @@
 
   int pointer_size = GetInferiorAddrSize(pid);
 
+  // Collect the list of all binaries that dyld knows about in
+  // the inferior process.
   std::vector<struct binary_image_information> all_image_infos;
   GetAllLoadedBinariesViaDYLDSPI(all_image_infos);
   uint32_t platform = GetPlatform();
@@ -1171,12 +1173,26 @@
   std::vector<struct binary_image_information> image_infos;
   const size_t macho_addresses_count = macho_addresses.size();
   const size_t all_image_infos_count = all_image_infos.size();
+
   for (size_t i = 0; i < macho_addresses_count; i++) {
+    bool found_matching_entry = false;
     for (size_t j = 0; j < all_image_infos_count; j++) {
       if (all_image_infos[j].load_address == macho_addresses[i]) {
         image_infos.push_back(all_image_infos[j]);
+        found_matching_entry = true;
       }
     }
+    if (!found_matching_entry) {
+      // dyld doesn't think there is a binary at this address,
+      // but maybe there isn't a binary YET - let's look in memory
+      // for a proper mach-o header etc and return what we can.
+      // We will have an empty filename for the binary (because dyld
+      // doesn't know about it yet) but we can read all of the mach-o
+      // load commands from memory directly.
+      struct binary_image_information entry;
+      entry.load_address = macho_addresses[i];
+      image_infos.push_back(entry);
+    }
   }
 
     const size_t image_infos_count = image_infos.size();