diff --git a/src/hb-wasm-api.h b/src/hb-wasm-api.h
index 805e89322..371f53d84 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_EXEC_ENV
+#define HB_WASM_EXEC_ENV
+#endif
 
 
 #ifndef bool_t
@@ -61,13 +64,16 @@ typedef uint32_t buffer_t;
 /* font */
 
 face_t
-HB_WASM_API (font_get_face) (font_t);
+HB_WASM_API (font_get_face) (HB_WASM_EXEC_ENV
+			     font_t);
 
 
 /* shape interface */
 
 bool_t
-HB_WASM_API (shape) (font_t, buffer_t);
+HB_WASM_API (shape) (HB_WASM_EXEC_ENV
+		     font_t,
+		     buffer_t);
 
 
 HB_WASM_END_DECLS
diff --git a/src/hb-wasm-api.hh b/src/hb-wasm-api.hh
index 0f63a1051..e0360d100 100644
--- a/src/hb-wasm-api.hh
+++ b/src/hb-wasm-api.hh
@@ -27,11 +27,14 @@
 
 #include "hb.h"
 
+#include <wasm_export.h>
 
 #define HB_WASM_API(x) HB_INTERNAL x
 #define HB_WASM_BEGIN_DECLS namespace hb { namespace wasm {
 #define HB_WASM_END_DECLS }}
 
+#define HB_WASM_EXEC_ENV wasm_exec_env_t exec_env,
+
 #include "hb-wasm-api.h"
 
 #undef HB_WASM_API
@@ -41,5 +44,29 @@
 
 #include "hb-wasm-font.hh"
 
+static void debugprint(wasm_exec_env_t exec_env, char *the_string, uint8_t len) {
+	printf("%*s", len, the_string);
+}
+
+
+  /* Define an array of NativeSymbol for the APIs to be exported.
+   * Note: the array must be static defined since runtime will keep it after registration
+   * For the function signature specifications, goto the link:
+   * https://github.com/bytecodealliance/wasm-micro-runtime/blob/main/doc/export_native_api.md
+   */
+
+#define NATIVE_SYMBOL(signature, name) {#name, (void *) hb::wasm::name, signature, NULL}
+  static NativeSymbol _hb_wasm_native_symbols[] =
+  {
+    NATIVE_SYMBOL ("(r)r",	font_get_face),
+    {
+	    "debugprint",
+	    (void *) debugprint,
+	    "($i)",
+	    NULL
+    }
+  };
+#undef NATIVE_SYMBOL
+
 
 #endif /* HB_WASM_API_HH */
diff --git a/src/hb-wasm-font.hh b/src/hb-wasm-font.hh
index 0223e676b..7fde34791 100644
--- a/src/hb-wasm-font.hh
+++ b/src/hb-wasm-font.hh
@@ -32,7 +32,8 @@ namespace wasm {
 
 
 face_t
-font_get_face (font_t)
+font_get_face (HB_WASM_EXEC_ENV
+	       font_t)
 {
   return 0;
 }
diff --git a/src/hb-wasm-shape.cc b/src/hb-wasm-shape.cc
index ccc337b1c..3aa77b5ba 100644
--- a/src/hb-wasm-shape.cc
+++ b/src/hb-wasm-shape.cc
@@ -32,8 +32,6 @@
 
 #include "hb-wasm-api.hh"
 
-#include <wasm_export.h>
-
 
 /*
  * shaper face data
@@ -46,10 +44,6 @@ struct hb_wasm_face_data_t {
   wasm_module_t wasm_module;
 };
 
-static void debugprint(wasm_exec_env_t exec_env, char *the_string, uint8_t len) {
-	printf("%*s", len, the_string);
-}
-
 static bool
 init_wasm ()
 {
@@ -60,21 +54,6 @@ init_wasm ()
   RuntimeInitArgs init_args;
   memset (&init_args, 0, sizeof (RuntimeInitArgs));
 
-  // Define an array of NativeSymbol for the APIs to be exported.
-  // Note: the array must be static defined since runtime
-  //            will keep it after registration
-  // For the function signature specifications, goto the link:
-  // https://github.com/bytecodealliance/wasm-micro-runtime/blob/main/doc/export_native_api.md
-
-  static NativeSymbol native_symbols[] = {
-  	{
-  		"debugprint",
-  		(void *)debugprint,
-  		"($i)",
-  		NULL
-  	}
-  };
-
   init_args.mem_alloc_type = Alloc_With_Allocator;
   init_args.mem_alloc_option.allocator.malloc_func = (void *) hb_malloc;
   init_args.mem_alloc_option.allocator.realloc_func = (void *) hb_realloc;
@@ -83,9 +62,9 @@ init_wasm ()
   init_args.mem_alloc_type = Alloc_With_System_Allocator;
 
   // Native symbols need below registration phase
-  init_args.n_native_symbols = sizeof(native_symbols) / sizeof(NativeSymbol);
+  init_args.n_native_symbols = ARRAY_LENGTH (_hb_wasm_native_symbols);
   init_args.native_module_name = "env";
-  init_args.native_symbols = native_symbols;
+  init_args.native_symbols = _hb_wasm_native_symbols;
 
   if (!wasm_runtime_full_init (&init_args))
   {