diff --git a/src/amp_conf.c b/src/amp_conf.c
index 481786b3f..d60496412 100644
--- a/src/amp_conf.c
+++ b/src/amp_conf.c
@@ -683,7 +683,7 @@ int HAMLIB_API amp_set_conf(AMP *amp, hamlib_token_t token, const char *val)
 {
     amp_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
 
-    if (!amp || !amp->caps)
+    if (!amp || !amp->caps || !val)
     {
         return -RIG_EINVAL;
     }
diff --git a/src/rot_conf.c b/src/rot_conf.c
index 5f204aed7..008a8f048 100644
--- a/src/rot_conf.c
+++ b/src/rot_conf.c
@@ -748,7 +748,7 @@ int HAMLIB_API rot_set_conf(ROT *rot, hamlib_token_t token, const char *val)
 {
     rot_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
 
-    if (!rot || !rot->caps)
+    if (!rot || !rot->caps || !val)
     {
         return -RIG_EINVAL;
     }