diff --git a/glx/single2.c b/glx/single2.c
index 18fd2c1bc..2848f73c5 100644
--- a/glx/single2.c
+++ b/glx/single2.c
@@ -272,15 +272,15 @@ __glXcombine_strings(const char *cext_string, const char *sext_string)
     clen = strlen(cext_string);
     slen = strlen(sext_string);
     if (clen > slen) {
-        combo_string = (char *) malloc(slen + 2);
-        s1 = (char *) malloc(slen + 2);
+        combo_string = (char *) calloc(1, slen + 2);
+        s1 = (char *) calloc(1, slen + 2);
         if (s1)
             strcpy(s1, sext_string);
         s2 = cext_string;
     }
     else {
-        combo_string = (char *) malloc(clen + 2);
-        s1 = (char *) malloc(clen + 2);
+        combo_string = (char *) calloc(1, clen + 2);
+        s1 = (char *) calloc(1, clen + 2);
         if (s1)
             strcpy(s1, cext_string);
         s2 = sext_string;
diff --git a/glx/vndcmds.c b/glx/vndcmds.c
index 4ffa5f19f..3f9587a88 100644
--- a/glx/vndcmds.c
+++ b/glx/vndcmds.c
@@ -126,7 +126,6 @@ static int dispatch_GLXQueryVersion(ClientPtr client)
 static int dispatch_GLXClientInfo(ClientPtr client)
 {
     GlxServerVendor *vendor;
-    void *requestCopy = NULL;
     size_t requestSize = client->req_len * 4;
 
     if (client->minorOp == X_GLXClientInfo) {
@@ -142,7 +141,7 @@ static int dispatch_GLXClientInfo(ClientPtr client)
     // We'll forward this request to each vendor library. Since a vendor might
     // modify the request data in place (e.g., for byte swapping), make a copy
     // of the request first.
-    requestCopy = malloc(requestSize);
+    void *requestCopy = calloc(1, requestSize);
     if (requestCopy == NULL) {
         return BadAlloc;
     }
diff --git a/glx/xfont.c b/glx/xfont.c
index 3e84369e8..05927f76c 100644
--- a/glx/xfont.c
+++ b/glx/xfont.c
@@ -64,7 +64,7 @@ __glXMakeBitmapFromGlyph(FontPtr font, CharInfoPtr pci)
     widthPadded = GLYPHWIDTHBYTESPADDED(pci);
 
     /*
-     ** Use the local buf if possible, otherwise malloc.
+     ** Use the local buf if possible, otherwise calloc.
      */
     allocBytes = widthPadded * h;
     if (allocBytes <= __GL_CHAR_BUF_SIZE) {
@@ -72,7 +72,7 @@ __glXMakeBitmapFromGlyph(FontPtr font, CharInfoPtr pci)
         allocbuf = 0;
     }
     else {
-        p = (unsigned char *) malloc(allocBytes);
+        p = calloc(1, allocBytes);
         if (!p)
             return BadAlloc;
         allocbuf = p;