diff --git a/include/asterisk/options.h b/include/asterisk/options.h
index d52b710c25f9a5a3af3878f10b11b0ab60544e4c..f94cf6e0e74235f50f027079067dac55a119cc84 100644
--- a/include/asterisk/options.h
+++ b/include/asterisk/options.h
@@ -113,7 +113,7 @@ extern int option_verbose;
 extern int option_debug;		/*!< Debugging */
 extern int option_maxcalls;		/*!< Maximum number of simultaneous channels */
 extern double option_maxload;
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 extern long option_minmemfree;		/*!< Minimum amount of free system memory - stop accepting calls if free memory falls below this watermark */
 #endif
 extern char defaultlanguage[];
diff --git a/main/asterisk.c b/main/asterisk.c
index ee4a4125a45b9f930ef054afc3273589dc33ff4f..99604408bf104c5a5f8e0088250c37ce73a070b0 100644
--- a/main/asterisk.c
+++ b/main/asterisk.c
@@ -80,7 +80,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include <grp.h>
 #include <pwd.h>
 #include <sys/stat.h>
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 #include <sys/sysinfo.h>
 #endif
 #ifdef linux
@@ -166,7 +166,7 @@ int option_debug;				/*!< Debug level */
 double option_maxload;				/*!< Max load avg on system */
 int option_maxcalls;				/*!< Max number of active calls */
 int option_maxfiles;				/*!< Max number of open file handles (files, sockets) */
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 long option_minmemfree;				/*!< Minimum amount of free system memory - stop accepting calls if free memory falls below this watermark */
 #endif
 
@@ -360,7 +360,7 @@ static int handle_show_settings(int fd, int argc, char *argv[])
 	ast_cli(fd, "  Verbosity:                   %d\n", option_verbose);
 	ast_cli(fd, "  Debug level:                 %d\n", option_debug);
 	ast_cli(fd, "  Max load avg:                %lf\n", option_maxload);
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 	ast_cli(fd, "  Min Free Memory:             %ld MB\n", option_minmemfree);
 #endif
 	if (localtime_r(&ast_startuptime, &tm)) {
@@ -416,7 +416,7 @@ static int handle_show_threads(int fd, int argc, char *argv[])
 	return 0;
 }
 
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 static const char show_sysinfo_help[] =
 "Usage: core show sysinfo\n"
 "       List current system information.\n";
@@ -1727,7 +1727,7 @@ static struct ast_cli_entry cli_asterisk[] = {
 	handle_show_threads, "Show running threads",
 	show_threads_help },
 
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 	{ { "core", "show", "sysinfo", NULL },
 	handle_show_sysinfo, "Show System Information",
 	show_sysinfo_help },
@@ -2525,7 +2525,7 @@ static void ast_readconfig(void)
 			ast_copy_string(ast_config_AST_SYSTEM_NAME, v->value, sizeof(ast_config_AST_SYSTEM_NAME));
 		} else if (!strcasecmp(v->name, "languageprefix")) {
 			ast_language_is_prefix = ast_true(v->value);
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 		} else if (!strcasecmp(v->name, "minmemfree")) {
 			/* specify the minimum amount of free memory to retain.  Asterisk should stop accepting new calls
 			 * if the amount of free memory falls below this watermark */
@@ -2605,7 +2605,7 @@ int main(int argc, char *argv[])
 	/* Check for options */
 	while ((c = getopt(argc, argv, "mtThfFdvVqprRgciInx:U:G:C:L:M:e:")) != -1) {
 		switch (c) {
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 		case 'e':
 			if ((sscanf(optarg, "%ld", &option_minmemfree) != 1) || (option_minmemfree < 0)) {
 				option_minmemfree = 0;
diff --git a/main/pbx.c b/main/pbx.c
index c90df8338a3ed45093e089634e2b1343adb6ca9d..e916411ffcef720f63b53753384f3c65fbbd9da4 100644
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -37,7 +37,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include <time.h>
 #include <sys/time.h>
 #include <limits.h>
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 #include <sys/sysinfo.h>
 #endif
 
@@ -2455,7 +2455,7 @@ static int increase_call_count(const struct ast_channel *c)
 {
 	int failed = 0;
 	double curloadavg;
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 	long curfreemem;
 	struct sysinfo sys_info;
 #endif
@@ -2474,7 +2474,7 @@ static int increase_call_count(const struct ast_channel *c)
 			failed = -1;
 		}
 	}
-#if HAVE_SYSINFO
+#if defined(HAVE_SYSINFO)
 	if (option_minmemfree) {
 		if (!sysinfo(&sys_info)) {
 			/* make sure that the free system memory is above the configured low watermark