diff --git a/React/CSSLayout/CSSLayout.c b/React/CSSLayout/CSSLayout.c
index ba1b10c6c..76f373493 100644
--- a/React/CSSLayout/CSSLayout.c
+++ b/React/CSSLayout/CSSLayout.c
@@ -219,6 +219,7 @@ void _CSSNodeMarkDirty(const CSSNodeRef node) {
 }
 
 void CSSNodeInsertChild(const CSSNodeRef node, const CSSNodeRef child, const uint32_t index) {
+  CSS_ASSERT(child->parent == NULL, "Child already has a parent, it must be removed first.");
   CSSNodeListInsert(node->children, child, index);
   child->parent = node;
   _CSSNodeMarkDirty(node);
@@ -2295,3 +2296,17 @@ void CSSNodeCalculateLayout(const CSSNodeRef node,
     }
   }
 }
+
+#ifdef CSS_ASSERT_FAIL_ENABLED
+static CSSAssertFailFunc gAssertFailFunc;
+
+void CSSAssertSetFailFunc(CSSAssertFailFunc func) {
+  gAssertFailFunc = func;
+}
+
+void CSSAssertFail(const char *message) {
+  if (gAssertFailFunc) {
+    (*gAssertFailFunc)(message);
+  }
+}
+#endif
diff --git a/React/CSSLayout/CSSLayout.h b/React/CSSLayout/CSSLayout.h
index ea532bbb1..9c4a10121 100644
--- a/React/CSSLayout/CSSLayout.h
+++ b/React/CSSLayout/CSSLayout.h
@@ -122,6 +122,10 @@ typedef CSSSize (*CSSMeasureFunc)(void *context,
                                   CSSMeasureMode heightMode);
 typedef void (*CSSPrintFunc)(void *context);
 
+#ifdef CSS_ASSERT_FAIL_ENABLED
+typedef void (*CSSAssertFailFunc)(const char *message);
+#endif
+
 // CSSNode
 WIN_EXPORT CSSNodeRef CSSNodeNew();
 WIN_EXPORT void CSSNodeInit(const CSSNodeRef node);
@@ -206,4 +210,10 @@ CSS_NODE_LAYOUT_PROPERTY(float, Width);
 CSS_NODE_LAYOUT_PROPERTY(float, Height);
 CSS_NODE_LAYOUT_PROPERTY(CSSDirection, Direction);
 
+#ifdef CSS_ASSERT_FAIL_ENABLED
+// Assert
+WIN_EXPORT void CSSAssertSetFailFunc(CSSAssertFailFunc func);
+WIN_EXPORT void CSSAssertFail(const char *message);
+#endif
+
 CSS_EXTERN_C_END
diff --git a/React/CSSLayout/CSSMacros.h b/React/CSSLayout/CSSMacros.h
index f4e29a1e3..b9b1faad5 100644
--- a/React/CSSLayout/CSSMacros.h
+++ b/React/CSSLayout/CSSMacros.h
@@ -33,8 +33,16 @@
 #define CSS_ABORT()
 #endif
 
-#define CSS_ASSERT(X, message)        \
-  if (!(X)) {                         \
-    fprintf(stderr, "%s\n", message); \
-    CSS_ABORT();                      \
+#if CSS_ASSERT_FAIL_ENABLED
+#define CSS_ERROR_FUNC(message) CSSAssertFail(message)
+#else
+#define CSS_ERROR_FUNC(message) fprintf(stderr, "%s", message)
+#endif
+
+#ifndef CSS_ASSERT
+#define CSS_ASSERT(X, message) \
+  if (!(X)) {                  \
+    CSS_ERROR_FUNC(message);   \
+    CSS_ABORT();               \
   }
+#endif