diff --git a/src/pystencilssfg/composer/basic_composer.py b/src/pystencilssfg/composer/basic_composer.py
index 9a870d9f107c766bb031f9c2cd5d8c2628e8dae1..75c023bc753d02b95f55190439f8b99262e23399 100644
--- a/src/pystencilssfg/composer/basic_composer.py
+++ b/src/pystencilssfg/composer/basic_composer.py
@@ -384,7 +384,7 @@ class SfgBasicComposer(SfgIComposer):
         if self._ctx.impl_file is None:
             seq.inline()
         if self._ctx.c_interfacing:
-            seq.externC()
+            seq._externC = True
 
         return seq
 
@@ -701,11 +701,6 @@ class SfgFunctionSequencerBase:
         self._inline = True
         return self
 
-    def externC(self):
-        """Mark this function as ``extern "C"``."""
-        self._externC = True
-        return self
-
     def constexpr(self):
         """Mark this function as ``constexpr``."""
         self._constexpr = True