diff --git a/ChangeLog b/ChangeLog
index 0f76805d79da60055fb015c133d704c6cbcee687..91c3fd78c19cf1146abbfa0a89886053c31dd3cb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-10-16  Niels Möller  <nisse@lysator.liu.se>
+
+	* aclocal.m4 (GMP_PROG_CC_FOR_BUILD): Add -g when compiling with
+	gcc.
+
 2017-09-24  Niels Möller  <nisse@lysator.liu.se>
 
 	* tools/pkcs1-conv.c (base64_decode_in_place): New helper
diff --git a/aclocal.m4 b/aclocal.m4
index debcf9c7dacbc5a680db69a8583b1890af4a342c..783dbc492b5c9dce437d4ac0aa431e7120ed2318 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -526,7 +526,7 @@ else
     fi
   fi
   if test "$CC_FOR_BUILD" = gcc ; then
-    CC_FOR_BUILD="$CC_FOR_BUILD -O"
+    CC_FOR_BUILD="$CC_FOR_BUILD -O -g"
   fi
 fi