diff --git a/src/os/tests/ifaddrs.c b/src/os/tests/ifaddrs.c
index cff5188..0e72065 100644
--- a/src/os/tests/ifaddrs.c
+++ b/src/os/tests/ifaddrs.c
@@ -16,9 +16,38 @@
           on a given host. To properly test all combinations the abstracted
           operating system functions must be mocked. */
 
+/* FIXME: It's possible that IPv6 is available in the network stack, but
+          disabled in the kernel. Travis CI for example has build environments
+          that do not have IPv6 enabled. */
+
+#ifdef OS_SOCKET_HAS_IPV6
+static int ipv6_enabled = 1;
+#endif
+
 CUnit_Suite_Initialize(os_getifaddrs)
 {
     os_osInit();
+
+#ifdef OS_SOCKET_HAS_IPV6
+#ifdef __linux
+    FILE *fh;
+    const char *const *path;
+    static const char *const paths[] = {
+        "/proc/sys/net/ipv6/conf/all/disable_ipv6",
+        "/proc/sys/net/ipv6/conf/default/disable_ipv6",
+        NULL
+    };
+
+    for (path = paths; ipv6_enabled == 1 && *path != NULL; path++) {
+         if ((fh = fopen(*path, "r")) != NULL) {
+             ipv6_enabled = (fgetc(fh) == '0');
+             fclose(fh);
+             fh = NULL;
+         }
+    }
+#endif /* __linux */
+#endif /* OS_SOCKET_HAS_IPV6 */
+
     return 0;
 }
 
@@ -90,52 +119,68 @@ CUnit_Test(os_getifaddrs, empty_filter)
 #ifdef OS_SOCKET_HAS_IPV6
 CUnit_Test(os_getifaddrs, ipv6)
 {
-    int err;
-    os_ifaddrs_t *ifa_root, *ifa;
-    const int afs[] = { AF_INET6, 0 };
+    if (ipv6_enabled == 1) {
+        int err;
+        int have_ipv6 = 0;
+        os_ifaddrs_t *ifa_root, *ifa;
+        const int afs[] = { AF_INET6, 0 };
 
-    err = os_getifaddrs(&ifa_root, afs);
-    CU_ASSERT_EQUAL_FATAL(err, 0);
-    for (ifa = ifa_root; ifa; ifa = ifa->next) {
-        CU_ASSERT_EQUAL(ifa->addr->sa_family, AF_INET6);
-        if (ifa->addr->sa_family == AF_INET6) {
-            if (ifa->flags & IFF_LOOPBACK) {
-                CU_ASSERT(os_sockaddrIsLoopback(ifa->addr));
-            } else {
-                CU_ASSERT(!os_sockaddrIsLoopback(ifa->addr));
+        err = os_getifaddrs(&ifa_root, afs);
+        CU_ASSERT_EQUAL_FATAL(err, 0);
+        for (ifa = ifa_root; ifa; ifa = ifa->next) {
+            CU_ASSERT_EQUAL(ifa->addr->sa_family, AF_INET6);
+            if (ifa->addr->sa_family == AF_INET6) {
+                have_ipv6 = 1;
+                if (ifa->flags & IFF_LOOPBACK) {
+                    CU_ASSERT(os_sockaddrIsLoopback(ifa->addr));
+                } else {
+                    CU_ASSERT(!os_sockaddrIsLoopback(ifa->addr));
+                }
             }
         }
-    }
 
-    os_freeifaddrs(ifa_root);
+        CU_ASSERT_EQUAL(have_ipv6, 1);
+
+        os_freeifaddrs(ifa_root);
+
+        CU_PASS("IPv6 enabled in test environment");
+    } else {
+        CU_PASS("IPv6 disabled in test environment");
+    }
 }
 
 /* Assume at least one IPv4 and one IPv6 interface are available when IPv6 is
    available on the platform. */
 CUnit_Test(os_getifaddrs, ipv4_n_ipv6)
 {
-    int err;
-    int have_ipv4 = 0;
-    int have_ipv6 = 0;
-    os_ifaddrs_t *ifa_root, *ifa;
-    const int afs[] = { AF_INET, AF_INET6, 0 };
+    if (ipv6_enabled == 1) {
+        int err;
+        int have_ipv4 = 0;
+        int have_ipv6 = 0;
+        os_ifaddrs_t *ifa_root, *ifa;
+        const int afs[] = { AF_INET, AF_INET6, 0 };
 
-    err = os_getifaddrs(&ifa_root, afs);
-    CU_ASSERT_EQUAL_FATAL(err, 0);
-    for (ifa = ifa_root; ifa; ifa = ifa->next) {
-      CU_ASSERT(ifa->addr->sa_family == AF_INET ||
-                ifa->addr->sa_family == AF_INET6);
-      if (ifa->addr->sa_family == AF_INET) {
-        have_ipv4 = 1;
-      } else if (ifa->addr->sa_family == AF_INET6) {
-        have_ipv6 = 1;
-      }
+        err = os_getifaddrs(&ifa_root, afs);
+        CU_ASSERT_EQUAL_FATAL(err, 0);
+        for (ifa = ifa_root; ifa; ifa = ifa->next) {
+            CU_ASSERT(ifa->addr->sa_family == AF_INET ||
+                      ifa->addr->sa_family == AF_INET6);
+            if (ifa->addr->sa_family == AF_INET) {
+                have_ipv4 = 1;
+            } else if (ifa->addr->sa_family == AF_INET6) {
+                have_ipv6 = 1;
+            }
+        }
+
+        CU_ASSERT_EQUAL(have_ipv4, 1);
+        CU_ASSERT_EQUAL(have_ipv6, 1);
+
+        os_freeifaddrs(ifa_root);
+
+        CU_PASS("IPv6 enabled in test environment");
+    } else {
+        CU_PASS("IPv6 disabled in test environment");
     }
-
-    CU_ASSERT_EQUAL(have_ipv4, 1);
-    CU_ASSERT_EQUAL(have_ipv6, 1);
-
-    os_freeifaddrs(ifa_root);
 }
 
 #endif /* OS_SOCKET_HAS_IPV6 */