--- a/src/interfaces/libpq/Makefile
+++ b/src/interfaces/libpq/Makefile
@@ -118,7 +118,7 @@ backend_src = $(top_srcdir)/src/backend
 libpq-refs-stamp: $(shlib)
 ifneq ($(enable_coverage), yes)
 ifeq (,$(filter aix solaris,$(PORTNAME)))
-	@if nm -A -u $< 2>/dev/null | grep -v __cxa_atexit | grep exit; then \
+	@if nm -A -u $< 2>/dev/null | grep " exit"; then \
 		echo 'libpq must not be calling any function which invokes exit'; exit 1; \
 	fi
 endif