diff --git a/src/mesa/main/texcompress_rgtc.c b/src/mesa/main/texcompress_rgtc.c
index a87493ec814..94c802170fd 100644
--- a/src/mesa/main/texcompress_rgtc.c
+++ b/src/mesa/main/texcompress_rgtc.c
@@ -49,7 +49,7 @@
 static void extractsrc_u( GLubyte srcpixels[4][4], const GLubyte *srcaddr,
 			  GLint srcRowStride, GLint numxpixels, GLint numypixels, GLint comps)
 {
-   GLubyte i, j;
+   GLint i, j;
    const GLubyte *curaddr;
    for (j = 0; j < numypixels; j++) {
       curaddr = srcaddr + j * srcRowStride * comps;
@@ -63,7 +63,7 @@ static void extractsrc_u( GLubyte srcpixels[4][4], const GLubyte *srcaddr,
 static void extractsrc_s( GLbyte srcpixels[4][4], const GLbyte *srcaddr,
 			  GLint srcRowStride, GLint numxpixels, GLint numypixels, GLint comps)
 {
-   GLubyte i, j;
+   GLint i, j;
    const GLbyte *curaddr;
    for (j = 0; j < numypixels; j++) {
       curaddr = srcaddr + j * srcRowStride * comps;
diff --git a/src/util/format/texcompress_s3tc_tmp.h b/src/util/format/texcompress_s3tc_tmp.h
index 79e1e55fd59..eb4ab460323 100644
--- a/src/util/format/texcompress_s3tc_tmp.h
+++ b/src/util/format/texcompress_s3tc_tmp.h
@@ -509,7 +509,7 @@ static void encodedxtcolorblockfaster( GLubyte *blkaddr, GLubyte srccolors[4][4]
 
    GLubyte *bestcolor[2];
    GLubyte basecolors[2][3];
-   GLubyte i, j;
+   GLint i, j;
    GLuint lowcv, highcv, testcv;
    GLboolean haveAlpha = GL_FALSE;
 
@@ -570,7 +570,8 @@ static void encodedxt5alpha(GLubyte *blkaddr, GLubyte srccolors[4][4][4],
    GLubyte alphabase[2], alphause[2];
    GLshort alphatest[2];
    GLuint alphablockerror1, alphablockerror2, alphablockerror3;
-   GLubyte i, j, aindex, acutValues[7];
+   GLint i, j;
+   GLubyte aindex, acutValues[7];
    GLubyte alphaenc1[16], alphaenc2[16], alphaenc3[16];
    GLboolean alphaabsmin = GL_FALSE;
    GLboolean alphaabsmax = GL_FALSE;
@@ -889,7 +890,7 @@ static void encodedxt5alpha(GLubyte *blkaddr, GLubyte srccolors[4][4][4],
 static void extractsrccolors( GLubyte srcpixels[4][4][4], const GLchan *srcaddr,
                          GLint srcRowStride, GLint numxpixels, GLint numypixels, GLint comps)
 {
-   GLubyte i, j, c;
+   GLint i, j, c;
    const GLchan *curaddr;
    for (j = 0; j < numypixels; j++) {
       curaddr = srcaddr + j * srcRowStride * comps;
diff --git a/src/util/texcompress_rgtc_tmp.h b/src/util/texcompress_rgtc_tmp.h
index 02566b12e7d..309db3cb82c 100644
--- a/src/util/texcompress_rgtc_tmp.h
+++ b/src/util/texcompress_rgtc_tmp.h
@@ -79,7 +79,8 @@ void TAG(encode_rgtc_ubyte)(TYPE *blkaddr, TYPE srccolors[4][4],
    TYPE alphabase[2], alphause[2];
    short alphatest[2] = { 0 };
    unsigned int alphablockerror1, alphablockerror2, alphablockerror3;
-   TYPE i, j, aindex, acutValues[7];
+   int i, j;
+   TYPE aindex, acutValues[7];
    TYPE alphaenc1[16], alphaenc2[16], alphaenc3[16];
    int alphaabsmin = 0, alphaabsmax = 0;
    short alphadist;