diff --git a/configure b/configure
index 8ac6bb4aa00..e5840e9a082 100755
--- a/configure
+++ b/configure
@@ -4756,6 +4756,66 @@ if test x"$pgac_cv_prog_cc_cflags__qnoansialias" = x"yes"; then
   CFLAGS="$CFLAGS -qnoansialias"
 fi
 
+  { $as_echo "$as_me:$LINENO: checking whether $CC supports -qlonglong" >&5
+$as_echo_n "checking whether $CC supports -qlonglong... " >&6; }
+if test "${pgac_cv_prog_cc_cflags__qlonglong+set}" = set; then
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+CFLAGS="$pgac_save_CFLAGS -qlonglong"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
+$as_echo "$ac_try_echo") >&5
+  (eval "$ac_compile") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && {
+	 test -z "$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest.$ac_objext; then
+  pgac_cv_prog_cc_cflags__qlonglong=yes
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	pgac_cv_prog_cc_cflags__qlonglong=no
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$pgac_save_CFLAGS"
+fi
+{ $as_echo "$as_me:$LINENO: result: $pgac_cv_prog_cc_cflags__qlonglong" >&5
+$as_echo "$pgac_cv_prog_cc_cflags__qlonglong" >&6; }
+if test x"$pgac_cv_prog_cc_cflags__qlonglong" = x"yes"; then
+  CFLAGS="$CFLAGS -qlonglong"
+fi
+
 elif test "$PORTNAME" = "hpux"; then
   # On some versions of HP-UX, libm functions do not set errno by default.
   # Fix that by using +Olibmerrno if the compiler recognizes it.
diff --git a/configure.in b/configure.in
index 1b8ccb06150..8a148e5ca10 100644
--- a/configure.in
+++ b/configure.in
@@ -443,6 +443,7 @@ elif test "$ICC" = yes; then
 elif test "$PORTNAME" = "aix"; then
   # AIX's xlc has to have strict aliasing turned off too
   PGAC_PROG_CC_CFLAGS_OPT([-qnoansialias])
+  PGAC_PROG_CC_CFLAGS_OPT([-qlonglong])
 elif test "$PORTNAME" = "hpux"; then
   # On some versions of HP-UX, libm functions do not set errno by default.
   # Fix that by using +Olibmerrno if the compiler recognizes it.
diff --git a/src/template/aix b/src/template/aix
index 04c97e7bd14..b566ff129df 100644
--- a/src/template/aix
+++ b/src/template/aix
@@ -7,7 +7,7 @@ if test "$GCC" != yes ; then
       CFLAGS="-O -qmaxmem=16384 -qsrcmsg"
       ;;
     *)
-      CFLAGS="-O2 -qmaxmem=16384 -qsrcmsg -qlonglong"
+      CFLAGS="-O2 -qmaxmem=16384 -qsrcmsg"
       ;;
   esac
 fi