diff --git a/lib/ntlm/Makefile.am b/lib/ntlm/Makefile.am
index 596cd942a..d496b34a8 100644
--- a/lib/ntlm/Makefile.am
+++ b/lib/ntlm/Makefile.am
@@ -6,7 +6,9 @@ AM_CPPFLAGS += $(INCLUDE_hcrypto)
 
 lib_LTLIBRARIES = libheimntlm.la
 
-include_HEADERS = heimntlm.h heimntlm-protos.h
+dist_include_HEADERS = heimntlm.h heimntlm-protos.h
+
+nodist_include_HEADERS = ntlm_err.h
 
 dist_libheimntlm_la_SOURCES = ntlm.c heimntlm.h