diff --git a/lldb/source/API/SBTarget.cpp b/lldb/source/API/SBTarget.cpp
--- a/lldb/source/API/SBTarget.cpp
+++ b/lldb/source/API/SBTarget.cpp
@@ -1586,8 +1586,16 @@
     if (path)
       module_spec.GetFileSpec().SetFile(path, FileSpec::Style::native);
 
-    if (uuid_cstr)
-      module_spec.GetUUID().SetFromStringRef(uuid_cstr);
+    if (uuid_cstr) {
+      llvm::StringRef uuid_str = llvm::StringRef(uuid_cstr).trim();
+      llvm::SmallVector<uint8_t, 20> bytes;
+      llvm::StringRef rest =
+          UUID::DecodeUUIDBytesFromString(uuid_str, bytes, 20);
+      // If the UUID string was consumed and it is not empty, let us use it for
+      // the lookup.
+      if (rest.empty() && bytes.size() > 0)
+        module_spec.GetUUID() = UUID::fromData(bytes);
+    }
 
     if (triple)
       module_spec.GetArchitecture() = Platform::GetAugmentedArchSpec(
diff --git a/lldb/test/API/python_api/addmodule-uuid/Makefile b/lldb/test/API/python_api/addmodule-uuid/Makefile
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/python_api/addmodule-uuid/Makefile
@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp
+
+include Makefile.rules
diff --git a/lldb/test/API/python_api/addmodule-uuid/TestAddModuleUUID.py b/lldb/test/API/python_api/addmodule-uuid/TestAddModuleUUID.py
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/python_api/addmodule-uuid/TestAddModuleUUID.py
@@ -0,0 +1,45 @@
+"""Test Python APIs for adding modules"""
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+class TestAddModuleUUID(TestBase):
+    mydir = TestBase.compute_mydir(__file__)
+    NO_DEBUG_INFO_TESTCASE = True
+
+    @skipIf(oslist=no_match(['linux']))
+    def test_add_existing_module_with_buildid_fast(self):
+      self.run_test_add_existing_module_with_uuid('-Wl,--build-id=fast')
+
+    @skipIf(oslist=no_match(['linux']))
+    def test_add_existing_module_with_buildid_sha1(self):
+      self.run_test_add_existing_module_with_uuid('-Wl,--build-id=sha1')
+
+    @skipIf(oslist=no_match(['linux']))
+    def test_add_existing_module_with_buildid_uuid(self):
+      self.run_test_add_existing_module_with_uuid('-Wl,--build-id=uuid')
+
+    def run_test_add_existing_module_with_uuid(self, ldflags):
+        d = self.getBuildFlags()
+        d['LD_EXTRAS'] = ldflags
+        self.build(dictionary=d)
+        (target, _, _, _) = lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.cpp"))
+        module = target.FindModule(target.GetExecutable())
+
+        # Check that adding the existing module gives that module back.
+        path = str(module.GetFileSpec())
+        uuid = module.GetUUIDString();
+        add_result = target.AddModule(path, "", uuid)
+        self.assertEqual(module, add_result)
+
+        # Change the UUID and check that adding with wrong UUID fails.
+        if len(uuid) != 0:
+          if uuid[0] == "0":
+            different_uuid = "1" + uuid[1:]
+          else:
+            different_uuid = "0" + uuid[1:]
+          add_result = target.AddModule(path, "", different_uuid)
+          self.assertTrue(not add_result.IsValid())
diff --git a/lldb/test/API/python_api/addmodule-uuid/main.cpp b/lldb/test/API/python_api/addmodule-uuid/main.cpp
new file mode 100644
--- /dev/null
+++ b/lldb/test/API/python_api/addmodule-uuid/main.cpp
@@ -0,0 +1,3 @@
+int main() {
+  return 0; // break here
+}