diff --git a/tests/unit-test-client.c b/tests/unit-test-client.c
index 4e2c683d..02fe8689 100644
--- a/tests/unit-test-client.c
+++ b/tests/unit-test-client.c
@@ -94,7 +94,7 @@ int main(int argc, char *argv[])
     int use_backend;
     int success = FALSE;
     int old_slave;
-    char *ip_or_device;
+    char *ip_or_device = NULL;
 
     if (argc > 1) {
         if (strcmp(argv[1], "tcp") == 0) {
diff --git a/tests/unit-test-server.c b/tests/unit-test-server.c
index ee844396..ea4455f1 100644
--- a/tests/unit-test-server.c
+++ b/tests/unit-test-server.c
@@ -42,7 +42,7 @@ int main(int argc, char *argv[])
     int use_backend;
     uint8_t *query;
     int header_length;
-    char *ip_or_device;
+    char *ip_or_device = NULL;
 
     if (argc > 1) {
         if (strcmp(argv[1], "tcp") == 0) {