diff --git a/lib/Makefile.am b/lib/Makefile.am
index 943eec28f931f3490c079c5927423ceb7823db3d..199f26ca5167f8ee68399774ae9130b51c08d03a 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -75,7 +75,7 @@ libcurl_la_SOURCES = arpa_telnet.h file.c netrc.h timeval.c base64.c	\
   content_encoding.c content_encoding.h share.c share.h http_digest.c	\
   md5.c md5.h http_digest.h http_negotiate.c http_negotiate.h		\
   http_ntlm.c http_ntlm.h ca-bundle.h inet_pton.c inet_pton.h		\
-  strtoofft.c strtoofft.h curl_strerror.c
+  strtoofft.c strtoofft.h curl_strerror.c curl_strerror.h
 
 noinst_HEADERS = setup.h transfer.h