diff --git a/tests/libfixmath/Makefile b/tests/libfixmath/Makefile
index ce035be05c..4fa74dcc92 100644
--- a/tests/libfixmath/Makefile
+++ b/tests/libfixmath/Makefile
@@ -2,7 +2,7 @@ include ../Makefile.tests_common
 
 USEPKG += libfixmath
 USEMODULE += libfixmath
-USEMODULE += xtimer
+USEMODULE += test_utils_interactive_sync
 
 TEST_ON_CI_WHITELIST += all
 
diff --git a/tests/libfixmath/main.c b/tests/libfixmath/main.c
index 52f12f530c..48094637e1 100644
--- a/tests/libfixmath/main.c
+++ b/tests/libfixmath/main.c
@@ -31,8 +31,8 @@
 #include <stdio.h>
 
 #include "kernel_defines.h"
-#include "xtimer.h"
 #include "fix16.h"
+#include "test_utils/interactive_sync.h"
 
 #ifndef M_PI
 #   define M_PI 3.14159265359
@@ -186,8 +186,9 @@ static void unary_ops(void)
 
 int main(void)
 {
-    /* Delay output to prevent flooding of buffer */
-    xtimer_sleep(1);
+    /* Sync to prevent flooding of buffer */
+    test_utils_interactive_sync();
+
     puts("Unary.");
     unary_ops();
 
diff --git a/tests/libfixmath/tests/01-run.py b/tests/libfixmath/tests/01-run.py
index 29213751f7..21e42d95fa 100755
--- a/tests/libfixmath/tests/01-run.py
+++ b/tests/libfixmath/tests/01-run.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 
 import sys
-from testrunner import run
+from testrunner import run, test_utils_interactive_sync
 
 
 def expect_unary(child):
@@ -31,6 +31,7 @@ def expect_binary(child):
 
 
 def testfunc(child):
+    test_utils_interactive_sync(child)
     child.expect_exact('Unary.')
     expect_unary(child)
     child.expect_exact('Binary.')