diff --git a/configs/z16f2800100zcog/ostest/defconfig b/configs/z16f2800100zcog/ostest/defconfig
index 8ef26c93837..60cb0cc7bc9 100644
--- a/configs/z16f2800100zcog/ostest/defconfig
+++ b/configs/z16f2800100zcog/ostest/defconfig
@@ -144,8 +144,7 @@ CONFIG_EXAMPLE=ostest
 CONFIG_DEBUG=y
 CONFIG_DEBUG_VERBOSE=n
 CONFIG_MM_REGIONS=1
-CONFIG_ARCH_LOWPUTC=n
-CONFIG_ARCH_LOWGETC=n
+CONFIG_ARCH_LOWPUTC=y
 CONFIG_RR_INTERVAL=200
 CONFIG_SCHED_INSTRUMENTATION=n
 CONFIG_TASK_NAME_SIZE=0
diff --git a/configs/z16f2800100zcog/pashello/defconfig b/configs/z16f2800100zcog/pashello/defconfig
index ef17f420671..0569a311d61 100644
--- a/configs/z16f2800100zcog/pashello/defconfig
+++ b/configs/z16f2800100zcog/pashello/defconfig
@@ -144,8 +144,7 @@ CONFIG_EXAMPLE=pashello
 CONFIG_DEBUG=y
 CONFIG_DEBUG_VERBOSE=n
 CONFIG_MM_REGIONS=1
-CONFIG_ARCH_LOWPUTC=n
-CONFIG_ARCH_LOWGETC=n
+CONFIG_ARCH_LOWPUTC=y
 CONFIG_RR_INTERVAL=200
 CONFIG_SCHED_INSTRUMENTATION=n
 CONFIG_TASK_NAME_SIZE=0
diff --git a/configs/z8encore000zco/ostest/defconfig b/configs/z8encore000zco/ostest/defconfig
index 0b4a31f24c5..c5b5b940593 100644
--- a/configs/z8encore000zco/ostest/defconfig
+++ b/configs/z8encore000zco/ostest/defconfig
@@ -144,8 +144,7 @@ CONFIG_EXAMPLE=ostest
 CONFIG_DEBUG=y
 CONFIG_DEBUG_VERBOSE=n
 CONFIG_MM_REGIONS=1
-CONFIG_ARCH_LOWPUTC=n
-CONFIG_ARCH_LOWGETC=n
+CONFIG_ARCH_LOWPUTC=y
 CONFIG_RR_INTERVAL=200
 CONFIG_SCHED_INSTRUMENTATION=n
 CONFIG_TASK_NAME_SIZE=0