diff --git a/os/mitauth.c b/os/mitauth.c
index a268f62f9..eb5ca3998 100644
--- a/os/mitauth.c
+++ b/os/mitauth.c
@@ -62,7 +62,7 @@ MitAddCookie(unsigned short data_length, const char *data, XID id)
     }
     new->next = mit_auth;
     mit_auth = new;
-    memmove(new->data, data, (int) data_length);
+    memcpy(new->data, data, (size_t) data_length);
     new->len = data_length;
     new->id = id;
     return 1;
diff --git a/os/rpcauth.c b/os/rpcauth.c
index 33260db72..0a752f013 100644
--- a/os/rpcauth.c
+++ b/os/rpcauth.c
@@ -70,7 +70,7 @@ authdes_ezdecode(const char *inmsg, int len)
         why = AUTH_FAILED; /* generic error, since there is no AUTH_BADALLOC */
         return NULL;
     }
-    memmove(temp_inmsg, inmsg, len);
+    memcpy(temp_inmsg, inmsg, len);
 
     memset((char *) &msg, 0, sizeof(msg));
     memset((char *) &r, 0, sizeof(r));
diff --git a/os/utils.c b/os/utils.c
index c9a8e7367..fe94912f3 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -1108,9 +1108,9 @@ set_font_authorizations(char **authorizations, int *authlen, void *client)
         *p++ = (len) >> 8;
         *p++ = (len & 0xff);
 
-        memmove(p, AUTHORIZATION_NAME, sizeof(AUTHORIZATION_NAME));
+        memcpy(p, AUTHORIZATION_NAME, sizeof(AUTHORIZATION_NAME));
         p += sizeof(AUTHORIZATION_NAME);
-        memmove(p, hnameptr, len);
+        memcpy(p, hnameptr, len);
         p += len;
 #if defined(IPv6) && defined(AF_INET6)
         if (ai) {
diff --git a/os/xdmauth.c b/os/xdmauth.c
index c35cade5b..ba446e013 100644
--- a/os/xdmauth.c
+++ b/os/xdmauth.c
@@ -356,8 +356,8 @@ XdmAddCookie(unsigned short data_length, const char *data, XID id)
         return 0;
     new->next = xdmAuth;
     xdmAuth = new;
-    memmove(new->key.data, key_bits, (int) 8);
-    memmove(new->rho.data, rho_bits, (int) 8);
+    memcpy(new->key.data, key_bits, 8);
+    memcpy(new->rho.data, rho_bits, 8);
     new->id = id;
     return 1;
 }
diff --git a/os/xdmcp.c b/os/xdmcp.c
index 093e30096..2b7255644 100644
--- a/os/xdmcp.c
+++ b/os/xdmcp.c
@@ -1409,7 +1409,7 @@ get_addr_by_name(const char *argtype,
         FatalError("Xserver: %s unknown host: %s\n", argtype, namestr);
     }
     if (hep->h_length == sizeof(struct in_addr)) {
-        memmove(&addr->sin_addr, hep->h_addr, hep->h_length);
+        memcpy(&addr->sin_addr, hep->h_addr, hep->h_length);
         *addrlen = sizeof(struct sockaddr_in);
         addr->sin_family = AF_INET;
         addr->sin_port = htons(port);