diff --git a/src/util/snprintf.c b/src/util/snprintf.c
index 9c12c3515e..ef6c5110c0 100644
--- a/src/util/snprintf.c
+++ b/src/util/snprintf.c
@@ -1,14 +1,14 @@
 /* snprintf.c - Formatted, length-limited print to a string */
 
 #include <afs/param.h>
-#if defined(AFS_OSF20_ENV) && !defined(AFS_DUX50_ENV) || defined(AFS_AIX32_ENV)
+#if defined(AFS_OSF20_ENV) && !defined(AFS_DUX50_ENV) || defined(AFS_AIX32_ENV) || (defined(AFS_SUN55_ENV) && !defined(AFS_SUN56_ENV))
 #include <sys/types.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <ctype.h>
 #include <netinet/in.h>
 #include <netdb.h>
-#if defined(AFS_AIX32_ENV)
+#if defined(AFS_AIX32_ENV) || defined(AFS_SUN55_ENV)
 #include <sys/socket.h>
 #endif