diff --git a/mesonbuild/dependencies/base.py b/mesonbuild/dependencies/base.py
index 5e1109dc4..4ef3603f7 100644
--- a/mesonbuild/dependencies/base.py
+++ b/mesonbuild/dependencies/base.py
@@ -977,7 +977,7 @@ class CMakeDependency(ExternalDependency):
     def _extra_cmake_opts(self):
         return []
 
-    def _map_module_list(self, modules: List[str]) -> List[str]:
+    def _map_module_list(self, modules: List[Tuple[str, bool]]) -> List[Tuple[str, bool]]:
         # Map the input module list to something else
         # This function will only be executed AFTER the initial CMake
         # interpreter pass has completed. Thus variables defined in the
@@ -1074,7 +1074,8 @@ class CMakeDependency(ExternalDependency):
         if self.cmakeinfo is None:
             raise self._gen_exception('Unable to obtain CMake system information')
 
-        modules = kwargs.get('modules', [])
+        modules = [(x, True) for x in kwargs.get('modules', [])]
+        modules += [(x, False) for x in kwargs.get('optional_modules', [])]
         cm_path = kwargs.get('cmake_module_path', [])
         cm_args = kwargs.get('cmake_args', [])
         if not isinstance(modules, list):
@@ -1255,7 +1256,7 @@ class CMakeDependency(ExternalDependency):
 
         return False
 
-    def _detect_dep(self, name: str, modules: List[str], args: List[str]):
+    def _detect_dep(self, name: str, modules: List[Tuple[str, bool]], args: List[str]):
         # Detect a dependency with CMake using the '--find-package' mode
         # and the trace output (stderr)
         #
@@ -1352,7 +1353,7 @@ class CMakeDependency(ExternalDependency):
                 lname = name.lower()
                 if '{}::{}'.format(lname, lname) == tg or lname == tg.replace('::', ''):
                     mlog.debug('Guessed CMake target \'{}\''.format(i))
-                    modules = [i]
+                    modules = [(i, True)]
                     break
 
         # Failed to guess a target --> try the old-style method
@@ -1380,8 +1381,11 @@ class CMakeDependency(ExternalDependency):
         compileDefinitions = []
         compileOptions = []
         libraries = []
-        for i in modules:
+        for i, required in modules:
             if i not in self.targets:
+                if not required:
+                    mlog.warning('CMake: Optional CMake target', mlog.bold(i), 'for', mlog.bold(name), 'was not found')
+                    continue
                 raise self._gen_exception('CMake: invalid CMake target {} for {}.\n'
                                           'Try to explicitly specify one or more targets with the "modules" property.\n'
                                           'Valid targets are:\n{}'.format(i, name, list(self.targets.keys())))
diff --git a/mesonbuild/dependencies/data/CMakeListsLLVM.txt b/mesonbuild/dependencies/data/CMakeListsLLVM.txt
index 3f064415a..d16e1b67b 100644
--- a/mesonbuild/dependencies/data/CMakeListsLLVM.txt
+++ b/mesonbuild/dependencies/data/CMakeListsLLVM.txt
@@ -17,8 +17,10 @@ endwhile()
 if(LLVM_FOUND)
   set(PACKAGE_FOUND TRUE)
 
-  llvm_map_components_to_libnames(llvm_libs ${LLVM_MESON_MODULES})
-  set(MESON_RESOLVED_LLVM_MODULES ${llvm_libs})
+  llvm_map_components_to_libnames(llvm_libs     ${LLVM_MESON_MODULES})
+  llvm_map_components_to_libnames(llvm_libs_opt ${LLVM_MESON_OPT_MODULES})
+  set(MESON_RESOLVED_LLVM_MODULES     ${llvm_libs})
+  set(MESON_RESOLVED_LLVM_MODULES_OPT ${llvm_libs_opt})
 
   # Check the following variables:
   # LLVM_PACKAGE_VERSION
diff --git a/mesonbuild/dependencies/dev.py b/mesonbuild/dependencies/dev.py
index 74e1412c6..8f0c2c5cd 100644
--- a/mesonbuild/dependencies/dev.py
+++ b/mesonbuild/dependencies/dev.py
@@ -401,7 +401,8 @@ class LLVMDependencyConfigTool(ConfigToolDependency):
 
 class LLVMDependencyCMake(CMakeDependency):
     def __init__(self, env, kwargs):
-        self.llvm_modules = kwargs.get('modules', [])
+        self.llvm_modules = stringlistify(extract_as_list(kwargs, 'modules'))
+        self.llvm_opt_modules = stringlistify(extract_as_list(kwargs, 'optional_modules'))
         super().__init__(name='LLVM', environment=env, language='cpp', kwargs=kwargs)
 
         # Extract extra include directories and definitions
@@ -415,10 +416,13 @@ class LLVMDependencyCMake(CMakeDependency):
         return 'CMakeListsLLVM.txt'
 
     def _extra_cmake_opts(self):
-        return ['-DLLVM_MESON_MODULES={}'.format(';'.join(self.llvm_modules))]
+        return ['-DLLVM_MESON_MODULES={}'.format(';'.join(self.llvm_modules)),
+                '-DLLVM_MESON_OPT_MODULES={}'.format(';'.join(self.llvm_opt_modules))]
 
     def _map_module_list(self, modules):
-        return self.get_cmake_var('MESON_RESOLVED_LLVM_MODULES')
+        modules = [(x, True) for x in self.get_cmake_var('MESON_RESOLVED_LLVM_MODULES')]
+        modules += [(x, False) for x in self.get_cmake_var('MESON_RESOLVED_LLVM_MODULES_OPT')]
+        return modules
 
     def need_threads(self):
         return True