diff --git a/src/hb-wasm-api.h b/src/hb-wasm-api.h
index 371f53d84..fa703be88 100644
--- a/src/hb-wasm-api.h
+++ b/src/hb-wasm-api.h
@@ -48,6 +48,9 @@ HB_WASM_BEGIN_DECLS
 #ifndef HB_WASM_API
 #define HB_WASM_API(x) x
 #endif
+#ifndef HB_WASM_INTERFACE
+#define HB_WASM_INTERFACE(x) x
+#endif
 #ifndef HB_WASM_EXEC_ENV
 #define HB_WASM_EXEC_ENV
 #endif
@@ -71,9 +74,9 @@ HB_WASM_API (font_get_face) (HB_WASM_EXEC_ENV
 /* shape interface */
 
 bool_t
-HB_WASM_API (shape) (HB_WASM_EXEC_ENV
-		     font_t,
-		     buffer_t);
+HB_WASM_INTERFACE (shape) (HB_WASM_EXEC_ENV
+			   font_t,
+			   buffer_t);
 
 
 HB_WASM_END_DECLS