diff --git a/lib/hx509/ks_dir.c b/lib/hx509/ks_dir.c
index dfce24a41..46e91f255 100644
--- a/lib/hx509/ks_dir.c
+++ b/lib/hx509/ks_dir.c
@@ -59,6 +59,12 @@ dir_init(hx509_context context,
 {
     *data = NULL;
 
+    if (residue == NULL || residue[0] == '\0') {
+        hx509_set_error_string(context, 0, EINVAL,
+                               "DIR file name not specified");
+        return EINVAL;
+    }
+
     {
 	struct stat sb;
 	int ret;
diff --git a/lib/hx509/ks_file.c b/lib/hx509/ks_file.c
index ee93537f0..18773c4ae 100644
--- a/lib/hx509/ks_file.c
+++ b/lib/hx509/ks_file.c
@@ -384,6 +384,12 @@ file_init_common(hx509_context context,
     pem_ctx.flags = flags;
     pem_ctx.c = NULL;
 
+    if (residue == NULL || residue[0] == '\0') {
+        hx509_set_error_string(context, 0, EINVAL,
+                               "PEM file name not specified");
+        return EINVAL;
+    }
+
     *data = NULL;
 
     if (lock == NULL)
diff --git a/lib/hx509/ks_p11.c b/lib/hx509/ks_p11.c
index 7fe5872a1..cfe62e869 100644
--- a/lib/hx509/ks_p11.c
+++ b/lib/hx509/ks_p11.c
@@ -820,6 +820,11 @@ p11_init(hx509_context context,
 
     *data = NULL;
 
+    if (residue == NULL || residue[0] == '\0') {
+	hx509_set_error_string(context, 0, EINVAL,
+			       "PKCS#11 store not specified");
+        return EINVAL;
+    }
     list = strdup(residue);
     if (list == NULL)
 	return ENOMEM;
diff --git a/lib/hx509/ks_p12.c b/lib/hx509/ks_p12.c
index f7b93a9ec..b4f66cb13 100644
--- a/lib/hx509/ks_p12.c
+++ b/lib/hx509/ks_p12.c
@@ -338,6 +338,12 @@ p12_init(hx509_context context,
 
     *data = NULL;
 
+    if (residue == NULL || residue[0] == '\0') {
+	hx509_set_error_string(context, 0, EINVAL,
+                               "PKCS#12 file not specified");
+        return EINVAL;
+    }
+
     if (lock == NULL)
 	lock = _hx509_empty_lock;