diff --git a/src/env.c b/src/env.c
index d8d126b..5b9f93a 100644
--- a/src/env.c
+++ b/src/env.c
@@ -180,17 +180,19 @@ void addFunc(const char *name, Object (*func)(Object, Object, struct Environment
 
 void deleteEnv(struct Environment *e)
 {
-    int i = 0;
-    while(e->strings[i]) {
-        free(e->strings[i]);
-        cleanObject(&e->objects[i]);
-        i++;
-    }
-    free(e->strings);
-    e->strings = NULL;
+    if (e->strings) {
+        int i = 0;
+        while(e->strings[i]) {
+            free(e->strings[i]);
+            cleanObject(&e->objects[i]);
+            i++;
+        }
+        free(e->strings);
+        e->strings = NULL;
 
-    free(e->objects);
-    e->objects = NULL;
+        free(e->objects);
+        e->objects = NULL;
+    }
 }
 
 struct symFunc {