diff --git a/LayoutTests/ChangeLog b/LayoutTests/ChangeLog
index e7b32fa..2bf704c 100644
--- a/LayoutTests/ChangeLog
+++ b/LayoutTests/ChangeLog
@@ -1,3 +1,10 @@
+2020-04-02  Ryan Haddad  <ryanhaddad@apple.com>
+
+        Unreviewed test gardening.
+
+        * platform/mac-wk1/TestExpectations: Mark http/tests/inspector/network/har/har-page-aggressive-gc.html
+        as slow for mac-wk1 debug.
+
 2020-04-02  Wenson Hsieh  <wenson_hsieh@apple.com>
 
         Avoid null deref after inserting a text field with a list attribute
diff --git a/LayoutTests/platform/mac-wk1/TestExpectations b/LayoutTests/platform/mac-wk1/TestExpectations
index d38e620..00baead 100644
--- a/LayoutTests/platform/mac-wk1/TestExpectations
+++ b/LayoutTests/platform/mac-wk1/TestExpectations
@@ -545,7 +545,8 @@
 http/tests/inspector/network/resource-sizes-network.html [ Failure ]
 http/tests/inspector/network/resource-sizes-memory-cache.html [ Failure ]
 http/tests/inspector/network/har/har-page.html [ Failure ]
-http/tests/inspector/network/har/har-page-aggressive-gc.html [ Failure ]
+[ Release ] http/tests/inspector/network/har/har-page-aggressive-gc.html [ Failure ]
+[ Debug ] http/tests/inspector/network/har/har-page-aggressive-gc.html [ Slow Failure ]
 
 # Local Overrides not available in WebKit1
 http/tests/inspector/network/local-resource-override-basic.html [ Failure ]