diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 0e6311a41..656ae5217 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -1824,6 +1824,7 @@ rule FORTRAN_DEP_HACK%s
         modre = re.compile(r"\s*\bmodule\b\s+(\w+)\s*$", re.IGNORECASE)
         submodre = re.compile(r"\s*\bsubmodule\b\s+\((\w+:?\w+)\)\s+(\w+)\s*$", re.IGNORECASE)
         module_files = {}
+        submodule_files = {}
         for s in target.get_sources():
             # FIXME, does not work for Fortran sources generated by
             # custom_target() and generator() as those are run after
@@ -1847,15 +1848,16 @@ rule FORTRAN_DEP_HACK%s
                     else:
                         submodmatch = submodre.match(line)
                         if submodmatch is not None:
-                            submodname = submodmatch.group(2).lower()
-                            if submodname in module_files:
+                            # '_' is arbitrarily used to distinguish submod from mod.
+                            submodname = '_' + submodmatch.group(2).lower()
+                            if submodname in submodule_files:
                                 raise InvalidArguments(
                                     'Namespace collision: submodule %s defined in '
                                     'two files %s and %s.' %
-                                    (submodname, module_files[submodname], s))
-                            module_files[submodname] = s
+                                    (submodname, submodule_files[submodname], s))
+                            submodule_files[submodname] = s
 
-        self.fortran_deps[target.get_basename()] = module_files
+        self.fortran_deps[target.get_basename()] = {**module_files, **submodule_files}
 
     def get_fortran_deps(self, compiler: FortranCompiler, src: str, target) -> List[str]:
         """
@@ -1865,6 +1867,63 @@ rule FORTRAN_DEP_HACK%s
         dirname = Path(self.get_target_private_dir(target))
         tdeps = self.fortran_deps[target.get_basename()]
         srcdir = Path(self.source_dir)
+<<<<<<< HEAD
+=======
+        with src.open(encoding='ascii', errors='ignore') as f:
+            for line in f:
+                usematch = usere.match(line)
+                if usematch is not None:
+                    usename = usematch.group(1).lower()
+                    if usename == 'intrinsic':  # this keeps the regex simpler
+                        continue
+                    if usename not in tdeps:
+                        # The module is not provided by any source file. This
+                        # is due to:
+                        #   a) missing file/typo/etc
+                        #   b) using a module provided by the compiler, such as
+                        #      OpenMP
+                        # There's no easy way to tell which is which (that I
+                        # know of) so just ignore this and go on. Ideally we
+                        # would print a warning message to the user but this is
+                        # a common occurrence, which would lead to lots of
+                        # distracting noise.
+                        continue
+                    srcfile = srcdir / tdeps[usename].fname
+                    if not srcfile.is_file():
+                        if srcfile.name != src.name:  # generated source file
+                            pass
+                        else:  # subproject
+                            continue
+                    elif srcfile.samefile(src):  # self-reference
+                        continue
+
+                    mod_name = compiler.module_name_to_filename(usename)
+                    mod_files.append(str(dirname / mod_name))
+                else:
+                    submodmatch = submodre.match(line)
+                    if submodmatch is not None:
+                        parents = submodmatch.group(1).lower().split(':')
+                        assert len(parents) in (1, 2), (
+                            'submodule ancestry must be specified as'
+                            ' ancestor:parent but Meson found {}'.parents)
+
+                        if len(parents) == 2:
+                            parents[1] = '_' + parents[1]
+
+                        for parent in parents:
+                            if parent not in tdeps:
+                                raise MesonException("submodule {} relies on parent module {} that was not found.".format(submodmatch.group(2).lower(), parent))
+                            submodsrcfile = srcdir / tdeps[parent].fname
+                            if not submodsrcfile.is_file():
+                                if submodsrcfile.name != src.name:  # generated source file
+                                    pass
+                                else:  # subproject
+                                    continue
+                            elif submodsrcfile.samefile(src):  # self-reference
+                                continue
+                            mod_name = compiler.module_name_to_filename(parent)
+                            mod_files.append(str(dirname / mod_name))
+>>>>>>> allow fortran submodule to have same name as module
 
         mod_files = _scan_fortran_file_deps(src, srcdir, dirname, tdeps, compiler)
         return mod_files