Index: src/tests/Makefile.am
===================================================================
--- src/tests/Makefile.am	(revision 6fb1921e9fe4edac74c6ffb62a115973f7a930f6)
+++ src/tests/Makefile.am	(revision 4f18de345b577edd78d514049636511fccecfac1)
@@ -79,4 +79,15 @@
 	@+${TEST_PY} --debug=${debug} -Iconcurrent
 
+# SKULLDUGGERY like libcfa/Makefile.am prevent extensionless headers from being generated
+# however, here it is more complicated because it must match the dependencies exactly
+# depencies seem to have the absolute path to the build directory and relative path
+# to the headers from there
+headers = $(shell find $(top_srcdir)/src/libcfa -type f ! -name "*.*")
+headers_real = $(shell realpath --relative-to=$(top_builddir) $(headers))
+headers_deps = $(addprefix $(abs_top_builddir)/, $(headers))
+$(headers_deps) :
+	echo "Dummy rule, should never be called"
+
+# implicit rule so not all test require a rule
 % : %.c $(CC)
 	$(COMPILE) $(abspath ${<}) -o ${@}
Index: src/tests/Makefile.in
===================================================================
--- src/tests/Makefile.in	(revision 6fb1921e9fe4edac74c6ffb62a115973f7a930f6)
+++ src/tests/Makefile.in	(revision 4f18de345b577edd78d514049636511fccecfac1)
@@ -309,4 +309,12 @@
 fstream_test_SOURCES = fstream_test.c
 avl_test_SOURCES = avltree/avl_test.c avltree/avl0.c avltree/avl1.c avltree/avl2.c avltree/avl3.c avltree/avl4.c avltree/avl-private.c
+
+# SKULLDUGGERY like libcfa/Makefile.am prevent extensionless headers from being generated
+# however, here it is more complicated because it must match the dependencies exactly
+# depencies seem to have the absolute path to the build directory and relative path
+# to the headers from there
+headers = $(shell find $(top_srcdir)/src/libcfa -type f ! -name "*.*")
+headers_real = $(shell realpath --relative-to=$(top_builddir) $(headers))
+headers_deps = $(addprefix $(abs_top_builddir)/, $(headers))
 all: all-am
 
@@ -626,5 +634,8 @@
 concurrency :
 	@+${TEST_PY} --debug=${debug} -Iconcurrent
-
+$(headers_deps) :
+	echo "Dummy rule, should never be called"
+
+# implicit rule so not all test require a rule
 % : %.c $(CC)
 	$(COMPILE) $(abspath ${<}) -o ${@}