diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
--- a/expat/lib/xmlparse.c
+++ b/expat/lib/xmlparse.c
@@ -444,16 +444,24 @@ typedef unsigned long long XmlBigCount;
 typedef struct accounting {
   XmlBigCount countBytesDirect;
   XmlBigCount countBytesIndirect;
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
   unsigned long debugLevel;
+#endif
+/* END MOZILLA CHANGE */
   float maximumAmplificationFactor; // >=1.0
   unsigned long long activationThresholdBytes;
 } ACCOUNTING;
 
 typedef struct entity_stats {
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
   unsigned int countEverOpened;
   unsigned int currentDepth;
   unsigned int maximumDepthSeen;
   unsigned long debugLevel;
+#endif
+/* END MOZILLA CHANGE */
 } ENTITY_STATS;
 #endif /* XML_GE == 1 */
 
@@ -611,18 +619,26 @@ static void parserInit(XML_Parser parser
 static float accountingGetCurrentAmplification(XML_Parser rootParser);
 static void accountingReportStats(XML_Parser originParser, const char *epilog);
 static void accountingOnAbort(XML_Parser originParser);
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
 static void accountingReportDiff(XML_Parser rootParser,
                                  unsigned int levelsAwayFromRootParser,
                                  const char *before, const char *after,
                                  ptrdiff_t bytesMore, int source_line,
                                  enum XML_Account account);
+#endif
+/* END MOZILLA CHANGE */
 static XML_Bool accountingDiffTolerated(XML_Parser originParser, int tok,
                                         const char *before, const char *after,
                                         int source_line,
                                         enum XML_Account account);
 
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
 static void entityTrackingReportStats(XML_Parser parser, ENTITY *entity,
                                       const char *action, int sourceLine);
+#endif
+/* END MOZILLA CHANGE */
 static void entityTrackingOnOpen(XML_Parser parser, ENTITY *entity,
                                  int sourceLine);
 static void entityTrackingOnClose(XML_Parser parser, ENTITY *entity,
@@ -632,8 +648,12 @@ static XML_Parser getRootParserOf(XML_Pa
                                   unsigned int *outLevelDiff);
 #endif /* XML_GE == 1 */
 
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
 static unsigned long getDebugLevel(const char *variableName,
                                    unsigned long defaultDebugLevel);
+#endif
+/* END MOZILLA CHANGE */
 
 #define poolStart(pool) ((pool)->start)
 #define poolLength(pool) ((pool)->ptr - (pool)->start)
@@ -1292,15 +1312,23 @@ parserInit(XML_Parser parser, const XML_
 
 #if XML_GE == 1
   memset(&parser->m_accounting, 0, sizeof(ACCOUNTING));
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
   parser->m_accounting.debugLevel = getDebugLevel("EXPAT_ACCOUNTING_DEBUG", 0u);
+#endif
+/* END MOZILLA CHANGE */
   parser->m_accounting.maximumAmplificationFactor
       = EXPAT_BILLION_LAUGHS_ATTACK_PROTECTION_MAXIMUM_AMPLIFICATION_DEFAULT;
   parser->m_accounting.activationThresholdBytes
       = EXPAT_BILLION_LAUGHS_ATTACK_PROTECTION_ACTIVATION_THRESHOLD_DEFAULT;
 
   memset(&parser->m_entity_stats, 0, sizeof(ENTITY_STATS));
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
   parser->m_entity_stats.debugLevel = getDebugLevel("EXPAT_ENTITY_DEBUG", 0u);
 #endif
+/* END MOZILLA CHANGE */
+#endif
 }
 
 /* moves list of bindings to m_freeBindingList */
@@ -8069,6 +8097,8 @@ accountingGetCurrentAmplification(XML_Pa
 
 static void
 accountingReportStats(XML_Parser originParser, const char *epilog) {
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
   const XML_Parser rootParser = getRootParserOf(originParser, NULL);
   assert(! rootParser->m_parentParser);
 
@@ -8084,6 +8114,8 @@ accountingReportStats(XML_Parser originP
           (void *)rootParser, rootParser->m_accounting.countBytesDirect,
           rootParser->m_accounting.countBytesIndirect,
           (double)amplificationFactor, epilog);
+#endif
+/* END MOZILLA CHANGE */
 }
 
 static void
@@ -8091,6 +8123,8 @@ accountingOnAbort(XML_Parser originParse
   accountingReportStats(originParser, " ABORTING\n");
 }
 
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
 static void
 accountingReportDiff(XML_Parser rootParser,
                      unsigned int levelsAwayFromRootParser, const char *before,
@@ -8127,6 +8161,8 @@ accountingReportDiff(XML_Parser rootPars
   }
   fprintf(stderr, "\"\n");
 }
+#endif
+/* END MOZILLA CHANGE */
 
 static XML_Bool
 accountingDiffTolerated(XML_Parser originParser, int tok, const char *before,
@@ -8174,11 +8210,15 @@ accountingDiffTolerated(XML_Parser origi
         || (amplificationFactor
             <= rootParser->m_accounting.maximumAmplificationFactor);
 
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
   if (rootParser->m_accounting.debugLevel >= 2u) {
     accountingReportStats(rootParser, "");
     accountingReportDiff(rootParser, levelsAwayFromRootParser, before, after,
                          bytesMore, source_line, account);
   }
+#endif
+/* END MOZILLA CHANGE */
 
   return tolerated;
 }
@@ -8197,6 +8237,8 @@ testingAccountingGetCountBytesIndirect(X
   return parser->m_accounting.countBytesIndirect;
 }
 
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
 static void
 entityTrackingReportStats(XML_Parser rootParser, ENTITY *entity,
                           const char *action, int sourceLine) {
@@ -8220,9 +8262,13 @@ entityTrackingReportStats(XML_Parser roo
       entity->is_param ? "%" : "&", entityName, action, entity->textLen,
       sourceLine);
 }
+#endif
+/* END MOZILLA CHANGE */
 
 static void
 entityTrackingOnOpen(XML_Parser originParser, ENTITY *entity, int sourceLine) {
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
   const XML_Parser rootParser = getRootParserOf(originParser, NULL);
   assert(! rootParser->m_parentParser);
 
@@ -8234,15 +8280,21 @@ entityTrackingOnOpen(XML_Parser originPa
   }
 
   entityTrackingReportStats(rootParser, entity, "OPEN ", sourceLine);
+#endif
+/* END MOZILLA CHANGE */
 }
 
 static void
 entityTrackingOnClose(XML_Parser originParser, ENTITY *entity, int sourceLine) {
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
   const XML_Parser rootParser = getRootParserOf(originParser, NULL);
   assert(! rootParser->m_parentParser);
 
   entityTrackingReportStats(rootParser, entity, "CLOSE", sourceLine);
   rootParser->m_entity_stats.currentDepth--;
+#endif
+/* END MOZILLA CHANGE */
 }
 
 static XML_Parser
@@ -8260,6 +8312,8 @@ getRootParserOf(XML_Parser parser, unsig
   return rootParser;
 }
 
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
 const char *
 unsignedCharToPrintable(unsigned char c) {
   switch (c) {
@@ -8781,9 +8835,13 @@ unsignedCharToPrintable(unsigned char c)
   }
   assert(0); /* never gets here */
 }
+#endif
+/* END MOZILLA CHANGE */
 
 #endif /* XML_GE == 1 */
 
+/* BEGIN MOZILLA CHANGE (don't report debug information) */
+#if 0
 static unsigned long
 getDebugLevel(const char *variableName, unsigned long defaultDebugLevel) {
   const char *const valueOrNull = getenv(variableName);
@@ -8802,3 +8860,5 @@ getDebugLevel(const char *variableName, 
 
   return debugLevel;
 }
+#endif
+/* END MOZILLA CHANGE */