diff --git a/CHANGELOG.md b/CHANGELOG.md
index 89cca0b..b49a776 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## master
 
+- Fix test suite compatibility with Rails main (pglite shims). ([@MattyMc](https://github.com/MattyMc))
+
 ## 2.1.1 (2026-01-13)
 
 - Fix defining store attributes after schema loading. ([@palkan][])
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index f628d06..bcfb59a 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -16,6 +16,41 @@
   ActiveRecord::Base.yaml_column_permitted_classes << Date
 end
 
+# pglite 0.1.1 is missing the connection methods that the latest Rails
+# calls (close, finished?, status), and it answers nil when Rails asks
+# parameter_status for the time zone. Getting no answer, Rails sets the
+# session time zone itself, and the wasm build cannot survive that
+# statement. It looks like it ships without time zone data, so any time
+# zone SET kills the instance for good. Answering "UTC" here means Rails
+# never sends it.
+#
+# The patch is pinned to this exact gem version so it retires itself on
+# the next pglite release. It also has to run before the first database
+# access. The support files connect at load time further down this file.
+if Gem::Version.new(PGlite::VERSION) <= Gem::Version.new("0.1.1")
+  # Rails main compares status to PG::CONNECTION_OK, a constant the pglite
+  # PG stub does not define. The real libpq value is 0.
+  PG.const_set(:CONNECTION_OK, 0) unless defined?(PG::CONNECTION_OK)
+
+  module PGliteRailsMainCompat
+    def close = nil
+
+    def finished? = false
+
+    def status = PG::CONNECTION_OK
+
+    def parameter_status(name)
+      # We cannot ask the embedded server for its time zone because that
+      # query also crashes it. Assume the wasm default of GMT, same as UTC.
+      return "UTC" if name.to_s.casecmp?("timezone")
+
+      super
+    end
+  end
+
+  PGlite::Connection.prepend(PGliteRailsMainCompat)
+end
+
 PGlite.install!(File.expand_path(File.join(__dir__, "../tmp/pglite")))
 
 ActiveRecord::Base.establish_connection(