diff --git a/Pipfile b/Pipfile
index aa760f3..441ac17 100644
--- a/Pipfile
+++ b/Pipfile
@@ -9,6 +9,7 @@ twine = "*"
 
 [packages]
 more-itertools = "*"
+markupsafe = "*"
 
 [requires]
 python_version = "3.8"
diff --git a/htbuilder/__init__.py b/htbuilder/__init__.py
index f6f5759..1cc326c 100644
--- a/htbuilder/__init__.py
+++ b/htbuilder/__init__.py
@@ -59,6 +59,7 @@
 
 """
 
+import markupsafe
 from more_itertools import collapse
 
 from .funcs import func
@@ -146,10 +147,14 @@ def __delattr__(self, name):
     def __str__(self):
         args = {
             "tag": _clean_name(self._tag),
-            "attrs": " ".join(
-                [f'{_clean_name(k)}="{v}"' for k, v in self._attrs.items()]
-            ),
-            "children": "".join([str(c) for c in self._children]),
+            "attrs": " ".join([
+                f'{_clean_name(k)}="{markupsafe.escape(v)}"'
+                for k, v in self._attrs.items()
+            ]),
+            "children": "".join([
+                markupsafe.escape(c) if isinstance(c, str) else str(c)
+                for c in self._children
+            ]),
         }
 
         if self._is_empty: