diff --git a/test/org/perses/grammar/c/PreprocessedCFileParserTest.kt b/test/org/perses/grammar/c/PreprocessedCFileParserTest.kt
index ed871319a..94f0724bb 100644
--- a/test/org/perses/grammar/c/PreprocessedCFileParserTest.kt
+++ b/test/org/perses/grammar/c/PreprocessedCFileParserTest.kt
@@ -21,6 +21,7 @@ class PreprocessedCFileParserTest {
     parseFile("clang_nullable_attribute.c")
   }
 
+  // FIXME: enable this when the C parse can parse clang-preprocessed code.
   @Ignore
   @Test
   fun testParseClang_preprocessed() {