diff --git a/src/hb-wasm-api-blob.hh b/src/hb-wasm-api-blob.hh
index fbff0ff1f..e3997d168 100644
--- a/src/hb-wasm-api-blob.hh
+++ b/src/hb-wasm-api-blob.hh
@@ -35,7 +35,7 @@ void
 blob_free (HB_WASM_EXEC_ENV
 	   ptr_t(blob_t) blobptr)
 {
-  HB_STRUCT_TYPE (blob_t, blob);
+  HB_OUT_PARAM (blob_t, blob);
   if (unlikely (!blob))
     return;
 
diff --git a/src/hb-wasm-api-buffer.hh b/src/hb-wasm-api-buffer.hh
index 39c65c5cf..d4f517421 100644
--- a/src/hb-wasm-api-buffer.hh
+++ b/src/hb-wasm-api-buffer.hh
@@ -39,7 +39,7 @@ void
 buffer_contents_free (HB_WASM_EXEC_ENV
 		      ptr_t(buffer_contents_t) contentsptr)
 {
-  HB_STRUCT_TYPE (buffer_contents_t, contents);
+  HB_OUT_PARAM (buffer_contents_t, contents);
   if (unlikely (!contents))
     return;
 
@@ -56,7 +56,7 @@ void
 			  ptr_t(buffer_contents_t) contentsptr,
 			  uint32_t size)
 {
-  HB_STRUCT_TYPE (buffer_contents_t, contents);
+  HB_OUT_PARAM (buffer_contents_t, contents);
   if (unlikely (!contents))
     return;
 
@@ -105,7 +105,7 @@ buffer_set_contents (HB_WASM_EXEC_ENV
 		     ptr_t(const buffer_contents_t) contentsptr)
 {
   HB_REF2OBJ (buffer);
-  HB_STRUCT_TYPE (buffer_contents_t, contents);
+  HB_OUT_PARAM (buffer_contents_t, contents);
   if (unlikely (!contents))
     return false;
 
diff --git a/src/hb-wasm-api-font.hh b/src/hb-wasm-api-font.hh
index ba80d6609..b1bc1fbd9 100644
--- a/src/hb-wasm-api-font.hh
+++ b/src/hb-wasm-api-font.hh
@@ -51,8 +51,8 @@ font_get_scale (HB_WASM_EXEC_ENV
 {
   HB_REF2OBJ (font);
 
-  HB_STRUCT_TYPE(int32_t, x_scale);
-  HB_STRUCT_TYPE(int32_t, y_scale);
+  HB_OUT_PARAM(int32_t, x_scale);
+  HB_OUT_PARAM(int32_t, y_scale);
 
   hb_font_get_scale (font, x_scale, y_scale);
 }
diff --git a/src/hb-wasm-api.hh b/src/hb-wasm-api.hh
index 646f50aad..19570698e 100644
--- a/src/hb-wasm-api.hh
+++ b/src/hb-wasm-api.hh
@@ -91,7 +91,7 @@ HB_INTERNAL extern hb_user_data_key_t _hb_wasm_ref_type_key;
   } \
   type &name = *_name_ptr
 
-#define HB_STRUCT_TYPE(type, name) \
+#define HB_OUT_PARAM(type, name) \
   type *name = nullptr; \
   HB_STMT_START { \
     if (likely (wasm_runtime_validate_app_addr (module_inst, \