diff --git a/reader.cpp b/reader.cpp
index dbf42195c..7e0c7e18c 100644
--- a/reader.cpp
+++ b/reader.cpp
@@ -336,7 +336,7 @@ public:
     /**
        Function for testing if the string can be returned
     */
-    int (*test_func)(const wchar_t *);
+    parser_test_error_bits_t (*test_func)(const wchar_t *);
 
     /**
        When this is true, the reader will exit
@@ -2548,7 +2548,7 @@ void reader_run_command(parser_t &parser, const wcstring &cmd)
 }
 
 
-int reader_shell_test(const wchar_t *b)
+parser_test_error_bits_t reader_shell_test(const wchar_t *b)
 {
     assert(b != NULL);
     wcstring bstr = b;
@@ -2557,7 +2557,7 @@ int reader_shell_test(const wchar_t *b)
     bstr.push_back(L'\n');
 
     parse_error_list_t errors;
-    int res = parse_util_detect_errors(bstr, &errors, true /* do accept incomplete */);
+    parser_test_error_bits_t res = parse_util_detect_errors(bstr, &errors, true /* do accept incomplete */);
 
     if (res & PARSER_TEST_ERROR)
     {
@@ -2579,7 +2579,7 @@ int reader_shell_test(const wchar_t *b)
    detection for general purpose, there are no invalid strings, so
    this function always returns false.
 */
-static int default_test(const wchar_t *b)
+static parser_test_error_bits_t default_test(const wchar_t *b)
 {
     return 0;
 }
@@ -2665,7 +2665,7 @@ void reader_set_highlight_function(highlight_function_t func)
     data->highlight_function = func;
 }
 
-void reader_set_test_function(int (*f)(const wchar_t *))
+void reader_set_test_function(parser_test_error_bits_t (*f)(const wchar_t *))
 {
     data->test_func = f;
 }
diff --git a/reader.h b/reader.h
index 3c82f5d18..744a360ed 100644
--- a/reader.h
+++ b/reader.h
@@ -17,6 +17,7 @@
 #include "common.h"
 #include "complete.h"
 #include "highlight.h"
+#include "parse_constants.h"
 
 class parser_t;
 class completion_t;
@@ -247,7 +248,7 @@ void reader_set_highlight_function(highlight_function_t);
    Specify function for testing if the command buffer contains syntax
    errors that must be corrected before returning.
 */
-void reader_set_test_function(int (*f)(const wchar_t *));
+void reader_set_test_function(parser_test_error_bits_t (*f)(const wchar_t *));
 
 /**
    Specify string of shell commands to be run in order to generate the
@@ -291,7 +292,7 @@ int reader_exit_forced();
    Test if the given shell command contains errors. Uses parser_test
    for testing. Suitable for reader_set_test_function().
 */
-int reader_shell_test(const wchar_t *b);
+parser_test_error_bits_t reader_shell_test(const wchar_t *b);
 
 /**
    Test whether the interactive reader is in search mode.