diff --git a/tests/llc/Makefile.am b/tests/llc/Makefile.am
index ee57c5f..ca0ed1d 100644
--- a/tests/llc/Makefile.am
+++ b/tests/llc/Makefile.am
@@ -1,8 +1,11 @@
+AM_CPPFLAGS = \
+	-I$(top_srcdir)/include/ \
+	$(NULL)
+
 AM_CFLAGS = \
 	-Wall \
 	$(LIBOSMOCORE_CFLAGS) \
 	$(LIBOSMOGSM_CFLAGS) \
-	-I$(top_srcdir)/include/ \
 	$(NULL)
 
 AM_LDFLAGS = \
diff --git a/tests/rlcmac/Makefile.am b/tests/rlcmac/Makefile.am
index 8d19656..9d1f5b0 100644
--- a/tests/rlcmac/Makefile.am
+++ b/tests/rlcmac/Makefile.am
@@ -1,8 +1,11 @@
+AM_CPPFLAGS = \
+	-I$(top_srcdir)/include/ \
+	$(NULL)
+
 AM_CFLAGS = \
 	-Wall \
 	$(LIBOSMOGSM_CFLAGS) \
 	$(LIBOSMOCORE_CFLAGS) \
-	-I$(top_srcdir)/include/ \
 	$(NULL)
 
 AM_LDFLAGS = \
diff --git a/tests/sndcp/Makefile.am b/tests/sndcp/Makefile.am
index aff2abf..603388e 100644
--- a/tests/sndcp/Makefile.am
+++ b/tests/sndcp/Makefile.am
@@ -1,8 +1,11 @@
+AM_CPPFLAGS = \
+	-I$(top_srcdir)/include/ \
+	$(NULL)
+
 AM_CFLAGS = \
 	-Wall \
 	$(LIBOSMOCORE_CFLAGS) \
 	$(LIBOSMOGSM_CFLAGS) \
-	-I$(top_srcdir)/include/ \
 	$(NULL)
 
 AM_LDFLAGS = \