diff --git a/hotdoc/extensions/c/c_extension.py b/hotdoc/extensions/c/c_extension.py
index 1cfd5b3..cff20c8 100644
--- a/hotdoc/extensions/c/c_extension.py
+++ b/hotdoc/extensions/c/c_extension.py
@@ -89,7 +89,7 @@ def get_clang_headers():
     try:
         # Clang 5.0+ can tell us directly
         resource_dir = subprocess.check_output(
-            ['clang', '--print-resource-dir']).strip().decode()
+            ['@clang@', '--print-resource-dir']).strip().decode()
         if len(resource_dir) > 0:
             include_dir = os.path.join(resource_dir, 'include')
             if os.path.exists(include_dir):
diff --git a/hotdoc/extensions/c/clang/cindex.py b/hotdoc/extensions/c/clang/cindex.py
index fc93fda..2eb8eaf 100644
--- a/hotdoc/extensions/c/clang/cindex.py
+++ b/hotdoc/extensions/c/clang/cindex.py
@@ -3937,20 +3937,23 @@ class Config:
         if Config.library_file:
             return Config.library_file
 
-        import platform
-        name = platform.system()
+        if Config.library_path:
+            import platform
+            name = platform.system()
 
-        if name == 'Darwin':
-            file = 'libclang.dylib'
-        elif name == 'Windows':
-            file = 'libclang.dll'
-        else:
-            file = 'libclang.so'
+            if name == 'Darwin':
+                file = 'libclang.dylib'
+            elif name == 'Windows':
+                file = 'libclang.dll'
+            else:
+                file = 'libclang.so'
 
-        if Config.library_path:
-            file = Config.library_path + '/' + file
+            if Config.library_path:
+                file = Config.library_path + '/' + file
+
+            return file
 
-        return file
+        return "@libclang@"
 
     def get_cindex_library(self):
         try: