diff --git a/t/CMakeLists.txt b/t/CMakeLists.txt
index 6fdee34..4ddbf54 100644
--- a/t/CMakeLists.txt
+++ b/t/CMakeLists.txt
@@ -7,12 +7,14 @@ add_executable("t_logfile"      "t_logfile.c" "${SRC_DIR}/strlcpy.c" "${SRC_DIR}
 add_executable("t_matches"      "t_matches.c" "${SRC_DIR}/strlcpy.c" "${SRC_DIR}/matches.c")
 add_executable("t_ipaddr"       "t_ipaddr.c"  "${SRC_DIR}/strlcpy.c" "${SRC_DIR}/matches.c" "${SRC_DIR}/ipaddr.c")
 add_executable("t_config_param" "t_config_param.c" "${SRC_DIR}/strlcpy.c" "${SRC_DIR}/config.c" "${SRC_DIR}/log.c")
+add_executable("t_backend_usage" "t_backend_usage.c" "${SRC_DIR}/strlcpy.c")
 
 add_test("tests/f2b_cmsg_*"    "t_cmsg")
 add_test("tests/f2b_logfile_*" "t_logfile")
 add_test("tests/f2b_matches_*" "t_matches")
 add_test("tests/f2b_ipaddr_*"  "t_ipaddr")
 add_test("tests/f2b_config_param*" "t_config_param")
+add_test("tests/backend/usage_*"   "t_backend_usage")
 
 add_executable("t_filter_preg" "t_filters.c" "${SRC_DIR}/filters/preg.c" "${SRC_DIR}/strlcpy.c")
 add_test("tests/filter/preg"   "t_filter_preg")
diff --git a/t/t_backend_usage.c b/t/t_backend_usage.c
new file mode 100644
index 0000000..d5e0af5
--- /dev/null
+++ b/t/t_backend_usage.c
@@ -0,0 +1,24 @@
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../src/strlcpy.h"
+#include "../src/backends/backend.h"
+#include "../src/backends/shared.c"
+
+int main() {
+  assert(usage_inc("test1") == 1);
+  assert(usage_inc("test1") == 2);
+  assert(usage_inc("test2") == 1);
+  assert(usage_inc("test1") == 3);
+
+  assert(usage_dec("test1") == 2);
+  assert(usage_dec("test1") == 1);
+  assert(usage_dec("test1") == 0);
+  assert(usage_dec("test1") == 0);
+
+  assert(usage_dec("test3") == 0);
+
+  return 0;
+}