diff --git a/lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.cpp b/lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.cpp
index 2e6528698d68e..557a781157303 100644
--- a/lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.cpp
+++ b/lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.cpp
@@ -9251,16 +9251,17 @@ bool SwiftASTContext::GetCompileUnitImportsImpl(
       validate_pcm = true;
 #endif
     }
-    
-    auto &pp_opts = m_clangimporter->getClangPreprocessor()
-      .getPreprocessorOpts();
-    pp_opts.DisablePCHOrModuleValidation =
-        validate_pcm ? clang::DisableValidationForModuleKind::None
-                     : clang::DisableValidationForModuleKind::All;
-    pp_opts.ModulesCheckRelocated = validate_pcm;
-
-    LOG_PRINTF(GetLog(LLDBLog::Types), "PCM validation is %s",
-               validate_pcm ? "disabled" : "enabled");
+
+    const auto &pp_opts =
+        m_clangimporter->getClangPreprocessor().getPreprocessorOpts();
+    // rdar://155232969
+    // pp_opts.DisablePCHOrModuleValidation =
+    //     validate_pcm ? clang::DisableValidationForModuleKind::None
+    //                  : clang::DisableValidationForModuleKind::All;
+    // pp_opts.ModulesCheckRelocated = validate_pcm;
+
+    if (!validate_pcm)
+      LOG_PRINTF(GetLog(LLDBLog::Types), "PCM validation cannot be disabled");
   }
   
   LOG_PRINTF(GetLog(LLDBLog::Types), "Importing dependencies of current CU");