diff --git a/testsuites/unittest/extended/signal/full/signal_test_017.cpp b/testsuites/unittest/extended/signal/full/signal_test_017.cpp
index 8069e7e501037833345e43c6a310fb16c954b34d..675e85694a15996cfd94c9b2f824ddb0d23777c6 100644
--- a/testsuites/unittest/extended/signal/full/signal_test_017.cpp
+++ b/testsuites/unittest/extended/signal/full/signal_test_017.cpp
@@ -53,7 +53,7 @@ static void *ThreadSetFunc2(void *arg)
     retValue = sigwait(&set, &sig);
     ICUNIT_ASSERT_EQUAL_NULL(retValue, 0, retValue);
 
-	return NULL;
+    return NULL;
 }
 
 static void *ThreadSetDfl(void *arg)
@@ -72,7 +72,7 @@ static void *ThreadSetDfl(void *arg)
     retValue = sigwait(&set, &sig);
     ICUNIT_ASSERT_EQUAL_NULL(retValue, 0, retValue);
 
-	return NULL;
+    return NULL;
 }
 
 static void *ThreadKill(void *arg)
@@ -91,7 +91,7 @@ static void *ThreadKill(void *arg)
     retValue = sigwait(&set, &sig);
     ICUNIT_ASSERT_EQUAL_NULL(retValue, 0, retValue);
 
-	return NULL;
+    return NULL;
 }
 
 static int TestMultiPthreadFatherProcessExit()