2 files changed, 10 insertions, 4 deletions
diff --git a/lib/erl_interface/test/all_SUITE_data/ei_runner.c b/lib/erl_interface/test/all_SUITE_data/ei_runner.c
index 2b0d6c856a..e9b4b2de57 100644
--- a/lib/erl_interface/test/all_SUITE_data/ei_runner.c
+++ b/lib/erl_interface/test/all_SUITE_data/ei_runner.c
@@ -255,12 +255,17 @@ do_report(file, line, ok)
  * Erlang side.
  */
 
-void do_fail(char* file, int line, char* reason)
+void do_fail(const char* file, int line, const char* reason, ...)
 {
+    va_list ap;
     char sbuf[2048];
+    char* sp = sbuf;
 
-    sbuf[0] = 'f';
-    sprintf(sbuf+1, "%s, line %d: %s", file, line, reason);
+    *sp++ = 'f';
+    sp += sprintf(sp, "%s, line %d: ", file, line);
+    va_start(ap, reason);
+    sp += vsprintf(sp, reason, ap);
+    va_end(ap);
     reply(sbuf, 1+strlen(sbuf+1));
 }
 
diff --git a/lib/erl_interface/test/all_SUITE_data/ei_runner.h b/lib/erl_interface/test/all_SUITE_data/ei_runner.h
index 62997d00a0..ca01a1d3ed 100644
--- a/lib/erl_interface/test/all_SUITE_data/ei_runner.h
+++ b/lib/erl_interface/test/all_SUITE_data/ei_runner.h
@@ -52,10 +52,11 @@ void free_packet(char*);
  */
 
 #define fail(reason) do_fail(__FILE__, __LINE__, reason)
+#define fail1(reason, a1) do_fail(__FILE__, __LINE__, reason, a1)
 #define report(ok) do_report(__FILE__, __LINE__, ok)
 
 void do_report(char* file, int line, int ok);
-void do_fail(char* file, int line, char* reason);
+void do_fail(const char* file, int line, const char* reason, ...);
 void send_buffer(char* buf, int size);
 void message(char* format, ...);