diff --git a/ext/pg_query/pg_query_deparse.c b/ext/pg_query/pg_query_deparse.c
index a62ae33..f37e5a0 100644
--- a/ext/pg_query/pg_query_deparse.c
+++ b/ext/pg_query/pg_query_deparse.c
@@ -9440,7 +9440,7 @@ static void deparseVariableShowStmt(StringInfo str, VariableShowStmt *variable_s
 	else if (strcmp(variable_show_stmt->name, "session_authorization") == 0)
 		appendStringInfoString(str, "SESSION AUTHORIZATION");
 	else if (strcmp(variable_show_stmt->name, "all") == 0)
-		appendStringInfoString(str, "SESSION ALL");
+		appendStringInfoString(str, "ALL");
 	else
 		appendStringInfoString(str, quote_identifier(variable_show_stmt->name));
 }
diff --git a/spec/lib/pg_query/deparse_spec.rb b/spec/lib/pg_query/deparse_spec.rb
index 9c205ac..c3c27bb 100644
--- a/spec/lib/pg_query/deparse_spec.rb
+++ b/spec/lib/pg_query/deparse_spec.rb
@@ -2181,5 +2181,19 @@
         it { is_expected.to eq query }
       end
     end
+
+    context 'SHOW' do
+      context 'show work_mem' do
+        let(:query) { 'SHOW work_mem' }
+
+        it { is_expected.to eq query }
+      end
+
+      context 'show all' do
+        let(:query) { 'SHOW ALL' }
+
+        it { is_expected.to eq query }
+      end
+    end
   end
 end