diff --git a/src/macros.rs b/src/macros.rs
index 660358d..e59be59 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -9,7 +9,7 @@ macro_rules! external_library
          )|*
 
          $(functions:
-            $($fname: ident($($farg: ty),*) -> $fret:ty),+;
+            $($fname: ident($($farg: ident: $fargt: ty),*) -> $fret:ty),+;
          )|*
 
          $(varargs: