diff --git a/snapshot/win/pe_image_reader.cc b/snapshot/win/pe_image_reader.cc
index 5ca53f2f2..35c9afe16 100644
--- a/snapshot/win/pe_image_reader.cc
+++ b/snapshot/win/pe_image_reader.cc
@@ -177,7 +177,8 @@ bool PEImageReader::DebugDirectoryInformation(UUID* uuid,
       continue;
 
     if (debug_directory.AddressOfRawData) {
-      if (debug_directory.SizeOfData < sizeof(CodeViewRecordPDB70)) {
+      if (debug_directory.SizeOfData <
+          offsetof(CodeViewRecordPDB70, pdb_name) + 1) {
         LOG(WARNING) << "CodeView debug entry of unexpected size in "
                      << module_subrange_reader_.name();
         continue;
@@ -200,6 +201,12 @@ bool PEImageReader::DebugDirectoryInformation(UUID* uuid,
         continue;
       }
 
+      if (data[data.size() - 1] != '\0') {
+        LOG(WARNING) << "CodeView debug entry missing NUL-terminator in "
+                     << module_subrange_reader_.name();
+        continue;
+      }
+
       CodeViewRecordPDB70* codeview =
           reinterpret_cast<CodeViewRecordPDB70*>(data.data());
       *uuid = codeview->uuid;