diff --git a/extensions/universalchardet/src/base/LangBulgarianModel.cpp b/extensions/universalchardet/src/base/LangBulgarianModel.cpp
index 79c575641aac..0f73282b878b 100644
--- a/extensions/universalchardet/src/base/LangBulgarianModel.cpp
+++ b/extensions/universalchardet/src/base/LangBulgarianModel.cpp
@@ -94,7 +94,7 @@ static const unsigned char win1251BulgarianCharToOrderMap[] =
 //first 1024 sequences:3.0618%
 //rest  sequences:     0.2992%
 //negative sequences:  0.0020% 
-static const char BulgarianLangModel[] = 
+static const PRUint8 BulgarianLangModel[] = 
 {
 0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,2,3,3,3,3,3,3,3,3,2,3,3,3,3,3,
 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,0,3,3,3,2,2,3,2,2,1,2,2,
diff --git a/extensions/universalchardet/src/base/LangCyrillicModel.cpp b/extensions/universalchardet/src/base/LangCyrillicModel.cpp
index 180c40e5fc52..d8e73e8a9e3e 100644
--- a/extensions/universalchardet/src/base/LangCyrillicModel.cpp
+++ b/extensions/universalchardet/src/base/LangCyrillicModel.cpp
@@ -167,7 +167,7 @@ static const unsigned char IBM866_CharToOrderMap[] =
 //first 1024 sequences: 2.3389%
 //rest  sequences:      0.1237%
 //negative sequences:   0.0009% 
-static const char RussianLangModel[] = 
+static const PRUint8 RussianLangModel[] = 
 {
 0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,1,1,3,3,3,3,1,3,3,3,2,3,2,3,3,
 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,0,3,2,2,2,2,2,0,0,2,
diff --git a/extensions/universalchardet/src/base/LangGreekModel.cpp b/extensions/universalchardet/src/base/LangGreekModel.cpp
index 13ce0ae9eb59..30c65dc7f98c 100644
--- a/extensions/universalchardet/src/base/LangGreekModel.cpp
+++ b/extensions/universalchardet/src/base/LangGreekModel.cpp
@@ -93,7 +93,7 @@ static const unsigned char win1253_CharToOrderMap[] =
 //first 1024 sequences:1.7001%
 //rest  sequences:     0.0359%
 //negative sequences:  0.0148% 
-static const char GreekLangModel[] = 
+static const PRUint8 GreekLangModel[] = 
 {
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
diff --git a/extensions/universalchardet/src/base/LangHebrewModel.cpp b/extensions/universalchardet/src/base/LangHebrewModel.cpp
index f86e68098296..a4e10addbcdb 100644
--- a/extensions/universalchardet/src/base/LangHebrewModel.cpp
+++ b/extensions/universalchardet/src/base/LangHebrewModel.cpp
@@ -76,7 +76,7 @@ static const unsigned char win1255_CharToOrderMap[] =
 //first 1024 sequences: 1.5981%
 //rest  sequences:      0.087%
 //negative sequences:   0.0015% 
-static const char HebrewLangModel[] = 
+static const PRUint8 HebrewLangModel[] = 
 {
 0,3,3,3,3,3,3,3,3,3,3,2,3,3,3,3,3,3,3,3,3,3,3,2,3,2,1,2,0,1,0,0,
 3,0,3,1,0,0,1,3,2,0,1,1,2,0,2,2,2,1,1,1,1,2,1,1,1,2,0,0,2,2,0,1,
diff --git a/extensions/universalchardet/src/base/LangHungarianModel.cpp b/extensions/universalchardet/src/base/LangHungarianModel.cpp
index 876826cdd63b..3af2f5882cf1 100644
--- a/extensions/universalchardet/src/base/LangHungarianModel.cpp
+++ b/extensions/universalchardet/src/base/LangHungarianModel.cpp
@@ -91,7 +91,7 @@ static const unsigned char win1250HungarianCharToOrderMap[] =
 //first 1024 sequences:5.2623%
 //rest  sequences:     0.8894%
 //negative sequences:  0.0009% 
-static const char HungarianLangModel[] = 
+static const PRUint8 HungarianLangModel[] = 
 {
 0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,1,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
 3,3,3,3,3,3,3,3,3,3,2,3,3,3,3,3,3,3,3,2,2,3,3,1,1,2,2,2,2,2,1,2,
diff --git a/extensions/universalchardet/src/base/LangThaiModel.cpp b/extensions/universalchardet/src/base/LangThaiModel.cpp
index aadc2dda9592..8145ffa1b2a2 100644
--- a/extensions/universalchardet/src/base/LangThaiModel.cpp
+++ b/extensions/universalchardet/src/base/LangThaiModel.cpp
@@ -78,7 +78,7 @@ static const unsigned char TIS620CharToOrderMap[] =
 //first 1024 sequences:7.3177%
 //rest  sequences:     1.0230%
 //negative sequences:  0.0436% 
-static const char ThaiLangModel[] = 
+static const PRUint8 ThaiLangModel[] = 
 {
 0,1,3,3,3,3,0,0,3,3,0,3,3,0,3,3,3,3,3,3,3,3,0,0,3,3,3,0,3,3,3,3,
 0,3,3,0,0,0,1,3,0,3,3,2,3,3,0,1,2,3,3,3,3,0,2,0,2,0,0,3,2,1,2,2,
diff --git a/extensions/universalchardet/src/base/nsSBCharSetProber.h b/extensions/universalchardet/src/base/nsSBCharSetProber.h
index b629feb346a2..d7180dcdfb0c 100644
--- a/extensions/universalchardet/src/base/nsSBCharSetProber.h
+++ b/extensions/universalchardet/src/base/nsSBCharSetProber.h
@@ -52,7 +52,7 @@
 typedef struct
 {
   const unsigned char* const charToOrderMap;    // [256] table use to find a char's order
-  const char* const precedenceMatrix;           // [SAMPLE_SIZE][SAMPLE_SIZE]; table to find a 2-char sequence's frequency
+  const PRUint8* const precedenceMatrix;  // [SAMPLE_SIZE][SAMPLE_SIZE]; table to find a 2-char sequence's frequency
   float  mTypicalPositiveRatio;     // = freqSeqs / totalSeqs 
   PRBool keepEnglishLetter;         // says if this script contains English characters (not implemented)
   const char* const charsetName;