diff --git a/src/core/execute.c b/src/core/execute.c
index 5a460b1678..2cdb688c3f 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -1620,6 +1620,7 @@ static int build_environment(
 
         assert(u);
         assert(c);
+        assert(p);
         assert(ret);
 
         our_env = new0(char*, 14);