diff -u -r config/c-compiler.m4 config/c-compiler.m4
--- config/c-compiler.m4	2014-07-21 21:18:03.000000000 +0200
+++ config/c-compiler.m4	2025-06-01 18:18:16.000000000 +0200
@@ -49,8 +49,10 @@
     return 0;
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_work());
+  return (! does_int64_work());
 }],
 [Ac_cachevar=yes],
 [Ac_cachevar=no],
diff -u -r config/c-library.m4 config/c-library.m4
--- config/c-library.m4	2014-07-21 21:18:03.000000000 +0200
+++ config/c-library.m4	2025-06-01 18:18:10.000000000 +0200
@@ -250,8 +250,10 @@
     return 0;			/* either multiply or snprintf is busted */
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_snprintf_work());
+  return (! does_int64_snprintf_work());
 }],
 [pgac_cv_snprintf_long_long_int_format=$pgac_format; break],
 [],
diff -u -r configure configure
--- configure	2014-07-21 21:18:03.000000000 +0200
+++ configure	2025-06-01 18:18:31.000000000 +0200
@@ -21832,8 +21832,10 @@
     return 0;
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_work());
+  return (! does_int64_work());
 }
 _ACEOF
 rm -f conftest$ac_exeext
@@ -21965,8 +21967,10 @@
     return 0;
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_work());
+  return (! does_int64_work());
 }
 _ACEOF
 rm -f conftest$ac_exeext
@@ -22119,8 +22123,10 @@
     return 0;			/* either multiply or snprintf is busted */
   return 1;
 }
+
+int
 main() {
-  exit(! does_int64_snprintf_work());
+  return (! does_int64_snprintf_work());
 }
 _ACEOF
 rm -f conftest$ac_exeext