diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 052b0db7..155bb128 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -4,6 +4,7 @@ stages:
 
 variables:
   BUILD_IMAGES_PROJECT: openconnect/build-images
+  ALPINE_BUILD: buildenv-alpine
   DEBIAN_BUILD: buildenv-debian
   FEDORA_BUILD: buildenv-fedora
   UBUNTU16_BUILD: buildenv-ubuntu
@@ -230,6 +231,24 @@ Coverity:
     paths:
       - cov-int/*.txt
 
+# Test building with musl
+musl/Alpine:
+  stage: testing
+  image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$ALPINE_BUILD
+  script:
+  - autoreconf -fvi
+  - ./configure --disable-maintainer-mode --without-docker-tests --with-werror
+  - make -j$JOBS
+  tags:
+  - shared
+  - linux
+  except:
+  - tags
+  artifacts:
+    expire_in: 1 day
+    untracked: true
+    when: on_failure
+
 Fedora:
   stage: testing
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$FEDORA_BUILD
@@ -255,7 +274,7 @@ Fedora:
     untracked: true
     when: always
 
-Fedora-noprocfs:
+noprocfs/Fedora:
   stage: testing
   image: $CI_REGISTRY/$BUILD_IMAGES_PROJECT:$FEDORA_BUILD
   script:
diff --git a/src/icmp-ping.c b/src/icmp-ping.c
index 7aed967d..58adef5a 100644
--- a/src/icmp-ping.c
+++ b/src/icmp-ping.c
@@ -200,9 +200,9 @@ int icmp_ping4(main_server_st * s, struct sockaddr_in *addr1)
 	pkt->icmp_cksum =
 	    in_cksum((unsigned short *) pkt, sizeof(packet1));
 
-	while ((c = sendto(pingsock, packet1, DEFDATALEN + ICMP_MINLEN, 0,
-			   (struct sockaddr *) addr1,
-			   sizeof(*addr1)) == -1) && retry(errno));
+	while (sendto(pingsock, packet1, DEFDATALEN + ICMP_MINLEN, 0,
+		      (struct sockaddr *) addr1,
+		      sizeof(*addr1) == -1) && retry(errno));
 	/* listen for replies */
 
 	now = time(0);
@@ -294,11 +294,10 @@ int icmp_ping6(main_server_st * s,
 	setsockopt(pingsock, SOL_RAW, IPV6_CHECKSUM,
 		   &sockopt, sizeof(sockopt));
 #endif
-	while ((c =
-		sendto(pingsock, packet1,
-		       DEFDATALEN + sizeof(struct icmp6_hdr), 0,
-		       (struct sockaddr *) addr1,
-		       sizeof(*addr1)) == -1) && retry(errno));
+	while (sendto(pingsock, packet1,
+		      DEFDATALEN + sizeof(struct icmp6_hdr), 0,
+		      (struct sockaddr *) addr1,
+		      sizeof(*addr1) == -1) && retry(errno));
 
 	/* listen for replies */
 	now = time(0);
diff --git a/src/occtl/nl.c b/src/occtl/nl.c
index 615e12e6..2f5197ca 100644
--- a/src/occtl/nl.c
+++ b/src/occtl/nl.c
@@ -53,7 +53,7 @@ int err;
 	}
 
 	if ((err = nl_connect(sock, NETLINK_ROUTE)) < 0) {
-		fprintf(stderr, "nl: error in nl_connect");
+		fprintf(stderr, "nl: error in nl_connect (%d)", err);
 		goto error;
 	}
 
diff --git a/src/occtl/occtl.c b/src/occtl/occtl.c
index 7d18771c..2793c640 100644
--- a/src/occtl/occtl.c
+++ b/src/occtl/occtl.c
@@ -286,7 +286,7 @@ unsigned check_cmd(const char *cmd, const char *input,
 {
 	char *t, *p;
 	unsigned len, tlen;
-	unsigned i, j, ret = 0;
+	unsigned i, ret = 0;
 	char prev;
 
 	while (whitespace(*input))
@@ -300,7 +300,7 @@ unsigned check_cmd(const char *cmd, const char *input,
 
 	prev = 0;
 	p = t;
-	for (i = j = 0; i < len; i++) {
+	for (i = 0; i < len; i++) {
 		if (!whitespace(prev) || !whitespace(input[i])) {
 			*p = input[i];
 			prev = input[i];
diff --git a/src/occtl/unix.c b/src/occtl/unix.c
index a7877a20..6bf17eb0 100644
--- a/src/occtl/unix.c
+++ b/src/occtl/unix.c
@@ -1210,7 +1210,7 @@ int common_info_cmd(UserListRep * args, FILE *out, cmd_params_st *params)
 			print_single_value(out, params, "Routes", "defaultroute", 1);
 		}
 
-		if ((r = print_list_entries(out, params, "No-routes", args->user[i]->no_routes, args->user[i]->n_no_routes, 1)) < 0)
+		if (print_list_entries(out, params, "No-routes", args->user[i]->no_routes, args->user[i]->n_no_routes, 1) < 0)
 			goto error_parse;
 
 		if (print_list_entries(out, params, "iRoutes", args->user[i]->iroutes, args->user[i]->n_iroutes, 1) < 0)
diff --git a/src/worker-privs.c b/src/worker-privs.c
index 6640b5ae..e01be0ab 100644
--- a/src/worker-privs.c
+++ b/src/worker-privs.c
@@ -29,7 +29,7 @@
 #include <sys/syscall.h>
 #include <seccomp.h>
 #include <sys/ioctl.h>
-#include <sys/signal.h>
+#include <signal.h>
 #include <errno.h>
 
 /* libseccomp 2.4.2 broke accidentally the API. Work around it. */