diff --git a/lib/librte_eal/include/rte_thread.h b/lib/librte_eal/include/rte_thread.h
index e640ea1857..8969b5d645 100644
--- a/lib/librte_eal/include/rte_thread.h
+++ b/lib/librte_eal/include/rte_thread.h
@@ -59,7 +59,9 @@ void rte_thread_get_affinity(rte_cpuset_t *cpusetp);
  *
  * @return
  *   On success, zero.
- *   On failure, a negative number.
+ *   On failure, a negative number and an error number is set in rte_errno.
+ *   rte_errno can be set to: ENOMEM - Memory allocation error.
+ *                            EOTHER - Specific OS error.
  */
 
 __rte_experimental
@@ -73,7 +75,9 @@ int rte_thread_tls_key_create(rte_tls_key *key, void (*destructor)(void *));
  *
  * @return
  *   On success, zero.
- *   On failure, a negative number.
+ *   On failure, a negative number and an error number is set in rte_errno.
+ *   rte_errno can be set to: EINVAL - Invalid parameter passed.
+ *                            EOTHER - Specific OS error.
  */
 __rte_experimental
 int rte_thread_tls_key_delete(rte_tls_key key);
@@ -88,7 +92,9 @@ int rte_thread_tls_key_delete(rte_tls_key key);
  *
  * @return
  *   On success, zero.
- *   On failure, a negative number.
+ *   On failure, a negative number and an error number is set in rte_errno.
+ *   rte_errno can be set to: EINVAL - Invalid parameter passed.
+ *                            EOTHER - Specific OS error.
  */
 __rte_experimental
 int rte_thread_tls_value_set(rte_tls_key key, const void *value);
@@ -102,6 +108,8 @@ int rte_thread_tls_value_set(rte_tls_key key, const void *value);
  * @return
  *   On success, value data pointer (can also be NULL).
  *   On failure, NULL and an error number is set in rte_errno.
+ *   rte_errno can be set to: EINVAL - Invalid parameter passed.
+ *                            EOTHER - Specific OS error.
  */
 __rte_experimental
 void *rte_thread_tls_value_get(rte_tls_key key);
diff --git a/lib/librte_eal/unix/rte_thread.c b/lib/librte_eal/unix/rte_thread.c
index 86ffeebc95..448dbdfcfd 100644
--- a/lib/librte_eal/unix/rte_thread.c
+++ b/lib/librte_eal/unix/rte_thread.c
@@ -24,6 +24,7 @@ rte_thread_tls_key_create(rte_tls_key *key, void (*destructor)(void *))
 	*key = malloc(sizeof(**key));
 	if ((*key) == NULL) {
 		RTE_LOG(DEBUG, EAL, "Cannot allocate TLS key.\n");
+		rte_errno = ENOMEM;
 		return -1;
 	}
 	err = pthread_key_create(&((*key)->thread_index), destructor);
@@ -31,6 +32,7 @@ rte_thread_tls_key_create(rte_tls_key *key, void (*destructor)(void *))
 		RTE_LOG(DEBUG, EAL, "pthread_key_create failed: %s\n",
 			 strerror(err));
 		free(*key);
+		rte_errno = EOTHER;
 		return -1;
 	}
 	return 0;
@@ -43,6 +45,7 @@ rte_thread_tls_key_delete(rte_tls_key key)
 
 	if (!key) {
 		RTE_LOG(DEBUG, EAL, "Invalid TLS key.\n");
+		rte_errno = EINVAL;
 		return -1;
 	}
 	err = pthread_key_delete(key->thread_index);
@@ -50,6 +53,7 @@ rte_thread_tls_key_delete(rte_tls_key key)
 		RTE_LOG(DEBUG, EAL, "pthread_key_delete failed: %s\n",
 			 strerror(err));
 		free(key);
+		rte_errno = EOTHER;
 		return -1;
 	}
 	free(key);
@@ -63,12 +67,14 @@ rte_thread_tls_value_set(rte_tls_key key, const void *value)
 
 	if (!key) {
 		RTE_LOG(DEBUG, EAL, "Invalid TLS key.\n");
+		rte_errno = EINVAL;
 		return -1;
 	}
 	err = pthread_setspecific(key->thread_index, value);
 	if (err) {
 		RTE_LOG(DEBUG, EAL, "pthread_setspecific failed: %s\n",
 			strerror(err));
+		rte_errno = EOTHER;
 		return -1;
 	}
 	return 0;
diff --git a/lib/librte_eal/windows/rte_thread.c b/lib/librte_eal/windows/rte_thread.c
index 2e2ab29177..d42f2cf62a 100644
--- a/lib/librte_eal/windows/rte_thread.c
+++ b/lib/librte_eal/windows/rte_thread.c
@@ -18,12 +18,14 @@ rte_thread_tls_key_create(rte_tls_key *key,
 	*key = malloc(sizeof(**key));
 	if ((*key) == NULL) {
 		RTE_LOG(DEBUG, EAL, "Cannot allocate TLS key.\n");
+		rte_errno = ENOMEM;
 		return -1;
 	}
 	(*key)->thread_index = TlsAlloc();
 	if ((*key)->thread_index == TLS_OUT_OF_INDEXES) {
 		RTE_LOG_WIN32_ERR("TlsAlloc()");
 		free(*key);
+		rte_errno = EOTHER;
 		return -1;
 	}
 	return 0;
@@ -34,11 +36,13 @@ rte_thread_tls_key_delete(rte_tls_key key)
 {
 	if (!key) {
 		RTE_LOG(DEBUG, EAL, "Invalid TLS key.\n");
+		rte_errno = EINVAL;
 		return -1;
 	}
 	if (!TlsFree(key->thread_index)) {
 		RTE_LOG_WIN32_ERR("TlsFree()");
 		free(key);
+		rte_errno = EOTHER;
 		return -1;
 	}
 	free(key);
@@ -52,12 +56,14 @@ rte_thread_tls_value_set(rte_tls_key key, const void *value)
 
 	if (!key) {
 		RTE_LOG(DEBUG, EAL, "Invalid TLS key.\n");
+		rte_errno = EINVAL;
 		return -1;
 	}
 	/* discard const qualifier */
 	p = (char *) (uintptr_t) value;
 	if (!TlsSetValue(key->thread_index, p)) {
 		RTE_LOG_WIN32_ERR("TlsSetValue()");
+		rte_errno = EOTHER;
 		return -1;
 	}
 	return 0;
@@ -76,7 +82,7 @@ rte_thread_tls_value_get(rte_tls_key key)
 	output = TlsGetValue(key->thread_index);
 	if (GetLastError() != ERROR_SUCCESS) {
 		RTE_LOG_WIN32_ERR("TlsGetValue()");
-		rte_errno = ENOEXEC;
+		rte_errno = EOTHER;
 		return NULL;
 	}
 	return output;
