diff --git a/tests/regression/result.c b/tests/regression/result.c
index 84a8a044dc..a13ef9c17a 100644
--- a/tests/regression/result.c
+++ b/tests/regression/result.c
@@ -10,7 +10,7 @@
 
 #include "result.h"
 
-char const* result_get_error_string(result_t result) {
+const char* result_get_error_string(result_t result) {
     switch (result_get_error(result)) {
         case result_error_ok:
             return "okay";
@@ -25,6 +25,6 @@ char const* result_get_error_string(result_t result) {
         case result_error_round_trip_error:
             return "round trip error";
         default:
-            return "unknown error - " + result_get_error(result);
+            return "unknown error";
     }
 }
diff --git a/tests/regression/result.h b/tests/regression/result.h
index 8a761ea4da..818ec356c8 100644
--- a/tests/regression/result.h
+++ b/tests/regression/result.h
@@ -94,7 +94,7 @@ static result_error_t result_get_error(result_t result) {
     return result.internal_error;
 }
 
-char const* result_get_error_string(result_t result);
+const char* result_get_error_string(result_t result);
 
 static result_data_t result_get_data(result_t result) {
     return result.internal_data;