diff --git a/src/aclocal.m4 b/src/aclocal.m4
index 6a142ae6b..879b97dbf 100644
--- a/src/aclocal.m4
+++ b/src/aclocal.m4
@@ -335,6 +335,9 @@ case "${host_os}" in
                      CFLAGS="-m64 $CFLAGS"
                      LDFLAGS="-m64 $LDFLAGS"
                   fi
+                  # Needed when building the old version of GMP.
+                  # Should be removed when moving to MPIR
+                  ABI="long"
                 fi      
                 # The Boehm-Weiser GC library shipped with Fink does not work
                 # well with our signal handler.
diff --git a/src/configure b/src/configure
index 70895b6fe..44ebf3f4f 100755
--- a/src/configure
+++ b/src/configure
@@ -4484,6 +4484,9 @@ case "${host_os}" in
                      CFLAGS="-m64 $CFLAGS"
                      LDFLAGS="-m64 $LDFLAGS"
                   fi
+                  # Needed when building the old version of GMP.
+                  # Should be removed when moving to MPIR
+                  ABI="long"
                 fi
                 # The Boehm-Weiser GC library shipped with Fink does not work
                 # well with our signal handler.