diff --git a/src/parse_execution.cpp b/src/parse_execution.cpp
index 8d338b66f..e4e4921b7 100644
--- a/src/parse_execution.cpp
+++ b/src/parse_execution.cpp
@@ -184,6 +184,7 @@ bool parse_execution_context_t::should_cancel_execution(const block_t *block) co
 
 parse_execution_context_t::execution_cancellation_reason_t
 parse_execution_context_t::cancellation_reason(const block_t *block) const {
+    UNUSED(block);
     if (shell_is_exiting()) {
         return execution_cancellation_exit;
     }
diff --git a/src/reader.cpp b/src/reader.cpp
index 4a18a7220..8e870590c 100644
--- a/src/reader.cpp
+++ b/src/reader.cpp
@@ -150,6 +150,7 @@ namespace {
 /// Test if the given string contains error. Since this is the error detection for general purpose,
 /// there are no invalid strings, so this function always returns false.
 parser_test_error_bits_t default_test(parser_t &parser, const wcstring &b) {
+    UNUSED(parser);
     UNUSED(b);
     return 0;
 }