diff --git a/tools/testing/selftests/alsa/Makefile b/tools/testing/selftests/alsa/Makefile
index 5af9ba8a4645..9a0ef194522c 100644
--- a/tools/testing/selftests/alsa/Makefile
+++ b/tools/testing/selftests/alsa/Makefile
@@ -6,7 +6,7 @@ LDLIBS += $(shell pkg-config --libs alsa)
ifeq ($(LDLIBS),)
LDLIBS += -lasound
endif
-CFLAGS += -L$(OUTPUT) -Wl,-rpath=./
+CFLAGS += $(KHDR_INCLUDES) -L$(OUTPUT) -Wl,-rpath=./
LDLIBS+=-lpthread
diff --git a/tools/testing/selftests/arm64/signal/Makefile b/tools/testing/selftests/arm64/signal/Makefile
index 8f5febaf1a9a..ae682ade615d 100644
--- a/tools/testing/selftests/arm64/signal/Makefile
+++ b/tools/testing/selftests/arm64/signal/Makefile
@@ -2,7 +2,7 @@
# Copyright (C) 2019 ARM Limited
# Additional include paths needed by kselftest.h and local headers
-CFLAGS += -D_GNU_SOURCE -std=gnu99 -I.
+CFLAGS += $(KHDR_INCLUDES) -std=gnu99 -I.
SRCS := $(filter-out testcases/testcases.c,$(wildcard testcases/*.c))
PROGS := $(patsubst %.c,%,$(SRCS))
diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile
index fb4472ddffd8..15e78ec7c55e 100644
--- a/tools/testing/selftests/exec/Makefile
+++ b/tools/testing/selftests/exec/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
CFLAGS = -Wall
CFLAGS += -Wno-nonnull
-CFLAGS += -D_GNU_SOURCE
+CFLAGS += $(KHDR_INCLUDES)
TEST_PROGS := binfmt_script.py
TEST_GEN_PROGS := execveat load_address_4096 load_address_2097152 load_address_16777216 non-regular
diff --git a/tools/testing/selftests/filesystems/overlayfs/Makefile b/tools/testing/selftests/filesystems/overlayfs/Makefile
index 56b2b48a765b..6c29c963c7a8 100644
--- a/tools/testing/selftests/filesystems/overlayfs/Makefile
+++ b/tools/testing/selftests/filesystems/overlayfs/Makefile
@@ -2,6 +2,6 @@
TEST_GEN_PROGS := dev_in_maps
-CFLAGS := -Wall -Werror
+CFLAGS := -Wall -Werror $(KHDR_INCLUDES)
include ../../lib.mk
diff --git a/tools/testing/selftests/hid/Makefile b/tools/testing/selftests/hid/Makefile
index 2b5ea18bde38..0661b34488ef 100644
--- a/tools/testing/selftests/hid/Makefile
+++ b/tools/testing/selftests/hid/Makefile
@@ -21,7 +21,7 @@ CXX ?= $(CROSS_COMPILE)g++
HOSTPKG_CONFIG := pkg-config
-CFLAGS += -g -O0 -rdynamic -Wall -Werror -I$(OUTPUT)
+CFLAGS += -g -O0 -rdynamic -Wall -Werror $(KHDR_INCLUDES) -I$(OUTPUT)
CFLAGS += -I$(OUTPUT)/tools/include
LDLIBS += -lelf -lz -lrt -lpthread
diff --git a/tools/testing/selftests/nci/Makefile b/tools/testing/selftests/nci/Makefile
index 47669a1d6a59..bbc5b8ec3b17 100644
--- a/tools/testing/selftests/nci/Makefile
+++ b/tools/testing/selftests/nci/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-CFLAGS += -Wl,-no-as-needed -Wall
+CFLAGS += -Wl,-no-as-needed -Wall $(KHDR_INCLUDES)
LDFLAGS += -lpthread
TEST_GEN_PROGS := nci_dev
diff --git a/tools/testing/selftests/prctl/Makefile b/tools/testing/selftests/prctl/Makefile
index 01dc90fbb509..1a0aefec9d6f 100644
--- a/tools/testing/selftests/prctl/Makefile
+++ b/tools/testing/selftests/prctl/Makefile
@@ -6,6 +6,8 @@ ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)
ifeq ($(ARCH),x86)
TEST_PROGS := disable-tsc-ctxt-sw-stress-test disable-tsc-on-off-stress-test \
disable-tsc-test set-anon-vma-name-test set-process-name
+
+CFLAGS += $(KHDR_INCLUDES)
all: $(TEST_PROGS)
include ../lib.mk
diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile
index cd95369254c0..9596014c10a0 100644
--- a/tools/testing/selftests/proc/Makefile
+++ b/tools/testing/selftests/proc/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
CFLAGS += -Wall -O2 -Wno-unused-function
-CFLAGS += -D_GNU_SOURCE
+CFLAGS += $(KHDR_INCLUDES)
LDFLAGS += -pthread
TEST_GEN_PROGS :=
diff --git a/tools/testing/selftests/riscv/mm/Makefile b/tools/testing/selftests/riscv/mm/Makefile
index c333263f2b27..715a21241113 100644
--- a/tools/testing/selftests/riscv/mm/Makefile
+++ b/tools/testing/selftests/riscv/mm/Makefile
@@ -3,7 +3,7 @@
# Originally tools/testing/arm64/abi/Makefile
# Additional include paths needed by kselftest.h and local headers
-CFLAGS += -D_GNU_SOURCE -std=gnu99 -I.
+CFLAGS += $(KHDR_INCLUDES) -std=gnu99 -I.
TEST_GEN_FILES := mmap_default mmap_bottomup
diff --git a/tools/testing/selftests/rtc/Makefile b/tools/testing/selftests/rtc/Makefile
index 55198ecc04db..654f9d58da3c 100644
--- a/tools/testing/selftests/rtc/Makefile
+++ b/tools/testing/selftests/rtc/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-CFLAGS += -O3 -Wl,-no-as-needed -Wall
+CFLAGS += -O3 -Wl,-no-as-needed -Wall $(KHDR_INCLUDES)
LDLIBS += -lrt -lpthread -lm
TEST_GEN_PROGS = rtctest
diff --git a/tools/testing/selftests/tmpfs/Makefile b/tools/testing/selftests/tmpfs/Makefile
index aa11ccc92e5b..bcdc1bb6d2e6 100644
--- a/tools/testing/selftests/tmpfs/Makefile
+++ b/tools/testing/selftests/tmpfs/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
CFLAGS += -Wall -O2
-CFLAGS += -D_GNU_SOURCE
+CFLAGS += $(KHDR_INCLUDES)
TEST_GEN_PROGS :=
TEST_GEN_PROGS += bug-link-o-tmpfile