diff --git a/components/style/context.rs b/components/style/context.rs
index bf12841f8a4..01043637a0d 100644
--- a/components/style/context.rs
+++ b/components/style/context.rs
@@ -94,7 +94,11 @@ impl Default for StyleSystemOptions {
     #[cfg(feature = "gecko")]
     fn default() -> Self {
         StyleSystemOptions {
-            disable_style_sharing_cache: get_env("DISABLE_STYLE_SHARING_CACHE"),
+            disable_style_sharing_cache:
+                // Disable the style sharing cache on opt builds until
+                // bug 1358693 is fixed, but keep it on debug builds to make
+                // sure we don't introduce correctness bugs.
+                if cfg!(debug_assertions) { get_env("DISABLE_STYLE_SHARING_CACHE") } else { true },
             dump_style_statistics: get_env("DUMP_STYLE_STATISTICS"),
         }
     }