diff --git a/src/hb-wasm-api-font.hh b/src/hb-wasm-api-font.hh
index d1401c7e0..4c641e971 100644
--- a/src/hb-wasm-api-font.hh
+++ b/src/hb-wasm-api-font.hh
@@ -136,6 +136,25 @@ HB_WASM_API (bool_t, font_copy_glyph_outline) (HB_WASM_EXEC_ENV
     return false;
   }
 
+  // TODO Check two buffers separately
+  if (hb_outline.points.length <= outline->n_points &&
+      hb_outline.contours.length <= outline->n_contours)
+  {
+    glyph_outline_point_t *points = (glyph_outline_point_t *) (validate_app_addr (outline->points, hb_outline.points.get_size ()) ? addr_app_to_native (outline->points) : nullptr);
+    uint32_t *contours = (uint32_t *) (validate_app_addr (outline->contours, hb_outline.contours.get_size ()) ? addr_app_to_native (outline->contours) : nullptr);
+
+    if (unlikely (!points || !contours))
+    {
+      outline->n_points = outline->n_contours = 0;
+      return false;
+    }
+
+    memcpy (points, hb_outline.points.arrayZ, hb_outline.points.get_size ());
+    memcpy (contours, hb_outline.contours.arrayZ, hb_outline.contours.get_size ());
+
+    return true;
+  }
+
   outline->n_points = hb_outline.points.length;
   outline->points = wasm_runtime_module_dup_data (module_inst,
 						  (const char *) hb_outline.points.arrayZ,
diff --git a/src/hb-wasm-api.h b/src/hb-wasm-api.h
index 0b09f4de9..9d8e9168f 100644
--- a/src/hb-wasm-api.h
+++ b/src/hb-wasm-api.h
@@ -252,6 +252,7 @@ typedef struct
   uint32_t n_contours;
   ptr_t(uint32_t) contours;
 } glyph_outline_t;
+#define GLYPH_OUTLINE_INIT {0, 0, 0, 0}
 
 HB_WASM_API (bool_t, font_copy_glyph_outline) (HB_WASM_EXEC_ENV
 					       ptr_d(font_t, font),
diff --git a/src/wasm/sample/c/shape-fallback.cc b/src/wasm/sample/c/shape-fallback.cc
index 0a2ab9e09..9bb3a688f 100644
--- a/src/wasm/sample/c/shape-fallback.cc
+++ b/src/wasm/sample/c/shape-fallback.cc
@@ -41,7 +41,7 @@ shape (void *shape_plan,
     contents.info[i].codepoint = font_get_glyph (font, contents.info[i].codepoint, 0);
     contents.pos[i].x_advance = font_get_glyph_h_advance (font, contents.info[i].codepoint);
 
-    glyph_outline_t outline;
+    glyph_outline_t outline = GLYPH_OUTLINE_INIT;
     font_copy_glyph_outline (font, contents.info[i].codepoint, &outline);
     debugprint1 ("num outline contours", outline.n_contours);
   }