diff --git a/config/c-library.m4 b/config/c-library.m4
index 0a7452c176247ffa27090b139c60d9e16fe04ac5..4ff8dae141ebe1cca82c1f3a138d74927097f669 100644
--- a/config/c-library.m4
+++ b/config/c-library.m4
@@ -42,7 +42,8 @@ if test "$ac_cv_member_struct_tm_tm_zone" = yes; then
 fi
 AC_CACHE_CHECK(for tzname, ac_cv_var_tzname,
 [AC_LINK_IFELSE([AC_LANG_PROGRAM(
-[[#include <time.h>
+[[#include <stdlib.h>
+#include <time.h>
 #ifndef tzname /* For SGI.  */
 extern char *tzname[]; /* RS6000 and others reject char **tzname.  */
 #endif
@@ -184,6 +185,7 @@ AC_DEFUN([PGAC_FUNC_SNPRINTF_LONG_LONG_INT_MODIFIER],
 AC_CACHE_VAL(pgac_cv_snprintf_long_long_int_modifier,
 [for pgac_modifier in 'll' 'q' 'I64'; do
 AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdio.h>
+#include <string.h>
 typedef long long int ac_int64;
 #define INT64_FORMAT "%${pgac_modifier}d"
 
diff --git a/configure b/configure
index 3eb0faf77dcacdc7050193f73f96ace8731c1a84..1021fd539ec95e4abe16d55a342f1df93f2553ba 100755
--- a/configure
+++ b/configure
@@ -11569,6 +11569,7 @@ if ${ac_cv_var_tzname+:} false; then :
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
+#include <stdlib.h>
 #include <time.h>
 #ifndef tzname /* For SGI.  */
 extern char *tzname[]; /* RS6000 and others reject char **tzname.  */
@@ -13754,6 +13755,7 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stdio.h>
+#include <string.h>
 typedef long long int ac_int64;
 #define INT64_FORMAT "%${pgac_modifier}d"