diff --git a/CSSLayout/CSSLayout.c b/CSSLayout/CSSLayout.c
index e8e4d21c..7c4e97d2 100644
--- a/CSSLayout/CSSLayout.c
+++ b/CSSLayout/CSSLayout.c
@@ -2497,17 +2497,3 @@ void CSSLog(CSSLogLevel level, const char *format, ...) {
   gLogger(level, format, args);
   va_end(args);
 }
-
-#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/CSSLayout/CSSLayout.h b/CSSLayout/CSSLayout.h
index 39f134f2..fb06d6d4 100644
--- a/CSSLayout/CSSLayout.h
+++ b/CSSLayout/CSSLayout.h
@@ -132,10 +132,6 @@ typedef CSSSize (*CSSMeasureFunc)(CSSNodeRef node,
 typedef void (*CSSPrintFunc)(CSSNodeRef node);
 typedef int (*CSSLogger)(CSSLogLevel level, const char *format, va_list args);
 
-#ifdef CSS_ASSERT_FAIL_ENABLED
-typedef void (*CSSAssertFailFunc)(const char *message);
-#endif
-
 // CSSNode
 WIN_EXPORT CSSNodeRef CSSNodeNew(void);
 WIN_EXPORT void CSSNodeInit(const CSSNodeRef node);
@@ -242,10 +238,4 @@ CSS_NODE_LAYOUT_PROPERTY(CSSDirection, Direction);
 WIN_EXPORT void CSSLayoutSetLogger(CSSLogger logger);
 WIN_EXPORT void CSSLog(CSSLogLevel level, const char *message, ...);
 
-#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/CSSLayout/CSSMacros.h b/CSSLayout/CSSMacros.h
index 65e68964..8d2375e5 100644
--- a/CSSLayout/CSSMacros.h
+++ b/CSSLayout/CSSMacros.h
@@ -33,16 +33,10 @@
 #define CSS_ABORT()
 #endif
 
-#if CSS_ASSERT_FAIL_ENABLED
-#define CSS_ERROR_FUNC(message) CSSAssertFail(message)
-#else
-#define CSS_ERROR_FUNC(message) CSSLog(CSSLogLevelError, "%s", message)
-#endif
-
 #ifndef CSS_ASSERT
-#define CSS_ASSERT(X, message) \
-  if (!(X)) {                  \
-    CSS_ERROR_FUNC(message);   \
-    CSS_ABORT();               \
+#define CSS_ASSERT(X, message)               \
+  if (!(X)) {                                \
+    CSSLog(CSSLogLevelError, "%s", message); \
+    CSS_ABORT();                             \
   }
 #endif
diff --git a/csharp/Facebook.CSSLayout/CSSAssert.cs b/csharp/Facebook.CSSLayout/CSSAssert.cs
deleted file mode 100644
index 848c9119..00000000
--- a/csharp/Facebook.CSSLayout/CSSAssert.cs
+++ /dev/null
@@ -1,35 +0,0 @@
-/**
- * Copyright (c) 2014-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- */
-
-using System;
-using System.Runtime.InteropServices;
-
-namespace Facebook.CSSLayout
-{
-    internal static class CSSAssert
-    {
-        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-        public delegate void FailFunc(string message);
-
-        private static bool _assertInitialized;
-        private static FailFunc _failFunc;
-
-        public static void Initialize()
-        {
-            if (!_assertInitialized)
-            {
-                _failFunc = (message) => {
-                    throw new InvalidOperationException(message);
-                };
-                Native.CSSAssertSetFailFunc(_failFunc);
-                _assertInitialized = true;
-            }
-        }
-    }
-}
diff --git a/csharp/Facebook.CSSLayout/CSSLogger.cs b/csharp/Facebook.CSSLayout/CSSLogger.cs
index c6c4ae37..60122f27 100644
--- a/csharp/Facebook.CSSLayout/CSSLogger.cs
+++ b/csharp/Facebook.CSSLayout/CSSLogger.cs
@@ -31,6 +31,11 @@ namespace Facebook.CSSLayout
                     {
                         Logger(level, message);
                     }
+
+                    if (level == CSSLogLevel.Error)
+                    {
+                        throw new InvalidOperationException(message);
+                    }
                 };
                 Native.CSSInteropSetLogger(_managedLogger);
                 _initialized = true;
diff --git a/csharp/Facebook.CSSLayout/CSSNode.cs b/csharp/Facebook.CSSLayout/CSSNode.cs
index 6267001e..1fea4c8a 100644
--- a/csharp/Facebook.CSSLayout/CSSNode.cs
+++ b/csharp/Facebook.CSSLayout/CSSNode.cs
@@ -26,7 +26,6 @@ namespace Facebook.CSSLayout
 
         public CSSNode()
         {
-            CSSAssert.Initialize();
             CSSLogger.Initialize();
 
             _cssNode = Native.CSSNodeNew();
diff --git a/csharp/Facebook.CSSLayout/Native.cs b/csharp/Facebook.CSSLayout/Native.cs
index 0d736f36..105652aa 100644
--- a/csharp/Facebook.CSSLayout/Native.cs
+++ b/csharp/Facebook.CSSLayout/Native.cs
@@ -24,10 +24,6 @@ namespace Facebook.CSSLayout
         public static extern void CSSInteropSetLogger(
             [MarshalAs(UnmanagedType.FunctionPtr)] CSSLogger.Func func);
 
-        [DllImport(DllName)]
-        public static extern void CSSAssertSetFailFunc(
-            [MarshalAs(UnmanagedType.FunctionPtr)] CSSAssert.FailFunc func);
-
         [DllImport(DllName)]
         public static extern IntPtr CSSNodeNew();
 
diff --git a/csharp/tests/Facebook.CSSLayout/test_macos.sh b/csharp/tests/Facebook.CSSLayout/test_macos.sh
index 27e39f64..c37247b8 100755
--- a/csharp/tests/Facebook.CSSLayout/test_macos.sh
+++ b/csharp/tests/Facebook.CSSLayout/test_macos.sh
@@ -27,6 +27,6 @@ if [ -d $NUNIT \
 fi
 
 cd "$( dirname "$0" )"
-clang -g -DCSS_ASSERT_FAIL_ENABLED -Wall -Wextra -dynamiclib -o libCSSLayout.dylib -I../../.. ../../../CSSLayout/*.c ../../CSSLayout/CSSInterop.cpp
+clang -g -Wall -Wextra -dynamiclib -o libCSSLayout.dylib -I../../.. ../../../CSSLayout/*.c ../../CSSLayout/CSSInterop.cpp
 mcs -debug -t:library -r:$NUNIT/nunit.framework.dll -out:CSSLayoutTest.dll *.cs ../../../csharp/Facebook.CSSLayout/*cs
 MONO_PATH=$NUNIT mono64 --debug $NUNIT/nunit-console.exe CSSLayoutTest.dll