diff --git a/callouts/tests/Makefile.am b/callouts/tests/Makefile.am
index db73ef937..a1f301ac3 100644
--- a/callouts/tests/Makefile.am
+++ b/callouts/tests/Makefile.am
@@ -5,6 +5,7 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)/libnm-core \
 	-I$(top_builddir)/libnm-core \
 	-I$(top_srcdir)/callouts \
+	-I$(top_builddir)/callouts \
 	-DNETWORKMANAGER_COMPILATION \
 	-DNM_VERSION_MAX_ALLOWED=NM_VERSION_NEXT_STABLE \
 	-DSRCDIR=\"$(abs_srcdir)\" \