diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 0257dd08..47f1478f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -18,6 +18,7 @@ build:
         - ./bootstrap
         - ./configure --with-linux-dir=/usr/src/linux-obj/$(uname -i)/default --enable-tty --with-devices=2 --enable-ccat
         - make -j8 all modules
+        - make -C lib symbol-version-check
         - make DISTCHECK_CONFIGURE_FLAGS="--with-linux-dir=/usr/src/linux-obj/$(uname -i)/default" distcheck
         - make dist
         - mkdir test_dist && cd test_dist && tar xzf ../ethercat-*.tar.gz && cd ethercat-*/
diff --git a/lib/Makefile.am b/lib/Makefile.am
index d0eaf6b0..6780a453 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -114,3 +114,17 @@ endif
 
 ethercat-config.cmake: $(srcdir)/ethercat-config.cmake.in Makefile
 	$(SED) -e 's,%libdir%,$(libdir),' -e 's,%includedir%,$(includedir),' $< > $@
+
+
+#-----------------------------------------------------------------------------
+
+.PHONY: symbol-version-check
+
+# check whether all symbols marked with EC_PUBLIC_API are listed in
+# libethercat.map
+
+symbol-version-check: libethercat.la
+	readelf --dyn-syms --wide $(builddir)/.libs/libethercat.so | \
+		awk '$$4 == "FUNC" && $$7 != "UND" && $$8 !~ /@LIBETHERCAT/ { print "Unversioned symbol: " $$8; err = 1; } END { exit err; }'
+
+#-----------------------------------------------------------------------------