diff --git a/src/lib/loader.c b/src/lib/loader.c
index cd1aa9e0..8b97690a 100644
--- a/src/lib/loader.c
+++ b/src/lib/loader.c
@@ -209,8 +209,9 @@ static char *get_or_create_temp_file(const char *prefix, EmbeddedData data,
     return NULL;
   }
 
+  // +3 for '/' separator, '-' separator, and NUL terminator
   char *path =
-      malloc(strlen(tmp_dir) + strlen(prefix) + strlen(data.digest) + 2);
+      malloc(strlen(tmp_dir) + 1 + strlen(prefix) + 1 + strlen(data.digest) + 1);
   if (path == NULL) {
     return NULL;
   }