diff --git a/cava/nightwatch/main.py b/cava/nightwatch/main.py
index d9fe3aab..3a549a2f 100644
--- a/cava/nightwatch/main.py
+++ b/cava/nightwatch/main.py
@@ -30,6 +30,8 @@ def main():
                              "suit.")
     parser.add_argument("--dump", action="store_true",
                         help="Output the API model in roughly the input format. This will loose information.")
+    parser.add_argument("--combine", "-C", type=str, action="append", dest="combine_files",
+                        help="Combine specifications with the current one.")
 
     args = parser.parse_args()
 
@@ -47,8 +49,13 @@ def main():
             errors = []
 
             from .parser import c
-            api = c.parse(args.inputfile, include_path=args.include_path or [], definitions=args.definitions or [],
-                          extra_args=(["-v"] if args.verbose else []) + (args.extra_args or []))
+            api = c.parse(
+                    args.inputfile,
+                    include_path=args.include_path or [],
+                    definitions=args.definitions or [],
+                    extra_args=(["-v"] if args.verbose else []) + (args.extra_args or []),
+                    combine_files=args.combine_files or [],
+            )
 
             if args.dump:
                 print(api)
diff --git a/cava/nightwatch/parser/c/__init__.py b/cava/nightwatch/parser/c/__init__.py
index 1c78cdbb..4228657a 100644
--- a/cava/nightwatch/parser/c/__init__.py
+++ b/cava/nightwatch/parser/c/__init__.py
@@ -1,4 +1,4 @@
-from typing import Dict
+from typing import Dict, List
 
 from .rules import *
 from .util import *
@@ -9,7 +9,12 @@
 deallocates_amount_prefix = "deallocates_amount_"
 
 
-def parse(filename: str, include_path, definitions, extra_args):
+def parse(
+        filename: str,
+        include_path: List[str],
+        definitions: List[str],
+        extra_args: List[str],
+        combine_files: List[str]):
     index = Index.create(True)
     includes = [s
                 for p in include_path