diff --git a/highfive/newpr.py b/highfive/newpr.py
index 063b536c..0411d83b 100755
--- a/highfive/newpr.py
+++ b/highfive/newpr.py
@@ -46,7 +46,7 @@ def welcome_msg(reviewer, config):
         link = "https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md"
     return raw_welcome % (text, link)
 
-warning_summary = '<img src="http://www.joshmatthews.net/warning.svg" alt="warning" height=20> **Warning** <img src="http://www.joshmatthews.net/warning.svg" alt="warning" height=20>\n\n%s'
+warning_summary = ':warning: **Warning** :warning:\n\n%s'
 unsafe_warning_msg = 'These commits modify **unsafe code**. Please review it carefully!'
 submodule_warning_msg = 'These commits modify **submodules**.'
 surprise_branch_warning = "Pull requests are usually filed against the %s branch for this repo, but this one is against %s. Please double check that you specified the right target!"
diff --git a/highfive/tests/test_newpr.py b/highfive/tests/test_newpr.py
index 4eaec77b..499974ea 100644
--- a/highfive/tests/test_newpr.py
+++ b/highfive/tests/test_newpr.py
@@ -674,7 +674,7 @@ def test_unexpected_branch(self):
         )
         self.mocks['modifies_submodule'].assert_called_with(self.diff)
 
-        expected_warning = """<img src="http://www.joshmatthews.net/warning.svg" alt="warning" height=20> **Warning** <img src="http://www.joshmatthews.net/warning.svg" alt="warning" height=20>
+        expected_warning = """:warning: **Warning** :warning:
 
 * Pull requests are usually filed against the master branch for this repo, but this one is against something-else. Please double check that you specified the right target!"""
         self.mocks['post_comment'].assert_called_with(
@@ -692,7 +692,7 @@ def test_modifies_submodule(self):
         )
         self.mocks['modifies_submodule'].assert_called_with(self.diff)
 
-        expected_warning = """<img src="http://www.joshmatthews.net/warning.svg" alt="warning" height=20> **Warning** <img src="http://www.joshmatthews.net/warning.svg" alt="warning" height=20>
+        expected_warning = """:warning: **Warning** :warning:
 
 * These commits modify **submodules**."""
         self.mocks['post_comment'].assert_called_with(
@@ -712,7 +712,7 @@ def test_unexpected_branch_modifies_submodule(self):
         )
         self.mocks['modifies_submodule'].assert_called_with(self.diff)
 
-        expected_warning = """<img src="http://www.joshmatthews.net/warning.svg" alt="warning" height=20> **Warning** <img src="http://www.joshmatthews.net/warning.svg" alt="warning" height=20>
+        expected_warning = """:warning: **Warning** :warning:
 
 * Pull requests are usually filed against the master branch for this repo, but this one is against something-else. Please double check that you specified the right target!
 * These commits modify **submodules**."""