diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
index 73f12ee..3113881 100644
--- a/doc/guides/prog_guide/rte_flow.rst
+++ b/doc/guides/prog_guide/rte_flow.rst
@@ -1695,6 +1695,25 @@ freed by the application, however its pointer can be considered valid only
 as long as its associated DPDK port remains configured. Closing the
 underlying device or unloading the PMD invalidates it.
 
+Helpers
+-------
+
+Error initializer
+~~~~~~~~~~~~~~~~~
+
+.. code-block:: c
+
+   static inline int
+   rte_flow_error_set(struct rte_flow_error *error,
+                      int code,
+                      enum rte_flow_error_type type,
+                      const void *cause,
+                      const char *message);
+
+This function initializes ``error`` (if non-NULL) with the provided
+parameters and sets ``rte_errno`` to ``code``. A negative error ``code`` is
+then returned.
+
 Caveats
 -------
 
@@ -1760,13 +1779,11 @@ the legacy filtering framework, which should eventually disappear.
   whatsoever). They only make sure these callbacks are non-NULL or return
   the ``ENOSYS`` (function not supported) error.
 
-This interface additionally defines the following helper functions:
+This interface additionally defines the following helper function:
 
 - ``rte_flow_ops_get()``: get generic flow operations structure from a
   port.
 
-- ``rte_flow_error_set()``: initialize generic flow error structure.
-
 More will be added over time.
 
 Device compatibility
diff --git a/drivers/net/mlx4/mlx4_flow.c b/drivers/net/mlx4/mlx4_flow.c
index 0885a91..018843b 100644
--- a/drivers/net/mlx4/mlx4_flow.c
+++ b/drivers/net/mlx4/mlx4_flow.c
@@ -955,9 +955,9 @@ mlx4_flow_isolate(struct rte_eth_dev *dev,
 		mlx4_mac_addr_del(priv);
 	} else if (mlx4_mac_addr_add(priv) < 0) {
 		priv->isolated = 1;
-		return -rte_flow_error_set(error, rte_errno,
-					   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-					   NULL, "cannot leave isolated mode");
+		return rte_flow_error_set(error, rte_errno,
+					  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+					  NULL, "cannot leave isolated mode");
 	}
 	return 0;
 }
diff --git a/drivers/net/tap/tap_flow.c b/drivers/net/tap/tap_flow.c
index 28d793f..ffc0b85 100644
--- a/drivers/net/tap/tap_flow.c
+++ b/drivers/net/tap/tap_flow.c
@@ -1462,7 +1462,7 @@ tap_flow_isolate(struct rte_eth_dev *dev,
 	return 0;
 error:
 	pmd->flow_isolate = 0;
-	return -rte_flow_error_set(
+	return rte_flow_error_set(
 		error, ENOTSUP, RTE_FLOW_ERROR_TYPE_UNSPECIFIED, NULL,
 		"TC rule creation failed");
 }
diff --git a/lib/librte_ether/rte_ethdev_version.map b/lib/librte_ether/rte_ethdev_version.map
index 92c9e29..e27f596 100644
--- a/lib/librte_ether/rte_ethdev_version.map
+++ b/lib/librte_ether/rte_ethdev_version.map
@@ -193,5 +193,6 @@ DPDK_17.11 {
 
 	rte_eth_dev_pool_ops_supported;
 	rte_eth_dev_reset;
+	rte_flow_error_set;
 
 } DPDK_17.08;
diff --git a/lib/librte_ether/rte_flow.c b/lib/librte_ether/rte_flow.c
index e276fb2..6659063 100644
--- a/lib/librte_ether/rte_flow.c
+++ b/lib/librte_ether/rte_flow.c
@@ -145,9 +145,9 @@ rte_flow_validate(uint16_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->validate))
 		return ops->validate(dev, attr, pattern, actions, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /* Create a flow rule on a given port. */
@@ -183,9 +183,9 @@ rte_flow_destroy(uint16_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->destroy))
 		return ops->destroy(dev, flow, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /* Destroy all flow rules associated with a port. */
@@ -200,9 +200,9 @@ rte_flow_flush(uint16_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->flush))
 		return ops->flush(dev, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /* Query an existing flow rule. */
@@ -220,9 +220,9 @@ rte_flow_query(uint16_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->query))
 		return ops->query(dev, flow, action, data, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
 }
 
 /* Restrict ingress traffic to the defined flow rules. */
@@ -238,9 +238,28 @@ rte_flow_isolate(uint16_t port_id,
 		return -rte_errno;
 	if (likely(!!ops->isolate))
 		return ops->isolate(dev, set, error);
-	return -rte_flow_error_set(error, ENOSYS,
-				   RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-				   NULL, rte_strerror(ENOSYS));
+	return rte_flow_error_set(error, ENOSYS,
+				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
+				  NULL, rte_strerror(ENOSYS));
+}
+
+/* Initialize flow error structure. */
+int
+rte_flow_error_set(struct rte_flow_error *error,
+		   int code,
+		   enum rte_flow_error_type type,
+		   const void *cause,
+		   const char *message)
+{
+	if (error) {
+		*error = (struct rte_flow_error){
+			.type = type,
+			.cause = cause,
+			.message = message,
+		};
+	}
+	rte_errno = code;
+	return -code;
 }
 
 /** Compute storage space needed by item specification. */
diff --git a/lib/librte_ether/rte_flow.h b/lib/librte_ether/rte_flow.h
index d37b0ad..a0ffb71 100644
--- a/lib/librte_ether/rte_flow.h
+++ b/lib/librte_ether/rte_flow.h
@@ -1322,6 +1322,30 @@ int
 rte_flow_isolate(uint16_t port_id, int set, struct rte_flow_error *error);
 
 /**
+ * Initialize flow error structure.
+ *
+ * @param[out] error
+ *   Pointer to flow error structure (may be NULL).
+ * @param code
+ *   Related error code (rte_errno).
+ * @param type
+ *   Cause field and error types.
+ * @param cause
+ *   Object responsible for the error.
+ * @param message
+ *   Human-readable error message.
+ *
+ * @return
+ *   Negative error code (errno value) and rte_errno is set.
+ */
+int
+rte_flow_error_set(struct rte_flow_error *error,
+		   int code,
+		   enum rte_flow_error_type type,
+		   const void *cause,
+		   const char *message);
+
+/**
  * Generic flow representation.
  *
  * This form is sufficient to describe an rte_flow independently from any
diff --git a/lib/librte_ether/rte_flow_driver.h b/lib/librte_ether/rte_flow_driver.h
index 8573cef..254d1cb 100644
--- a/lib/librte_ether/rte_flow_driver.h
+++ b/lib/librte_ether/rte_flow_driver.h
@@ -45,7 +45,6 @@
 
 #include <stdint.h>
 
-#include <rte_errno.h>
 #include "rte_ethdev.h"
 #include "rte_flow.h"
 
@@ -128,43 +127,6 @@ struct rte_flow_ops {
 };
 
 /**
- * Initialize generic flow error structure.
- *
- * This function also sets rte_errno to a given value.
- *
- * @param[out] error
- *   Pointer to flow error structure (may be NULL).
- * @param code
- *   Related error code (rte_errno).
- * @param type
- *   Cause field and error types.
- * @param cause
- *   Object responsible for the error.
- * @param message
- *   Human-readable error message.
- *
- * @return
- *   Error code.
- */
-static inline int
-rte_flow_error_set(struct rte_flow_error *error,
-		   int code,
-		   enum rte_flow_error_type type,
-		   const void *cause,
-		   const char *message)
-{
-	if (error) {
-		*error = (struct rte_flow_error){
-			.type = type,
-			.cause = cause,
-			.message = message,
-		};
-	}
-	rte_errno = code;
-	return code;
-}
-
-/**
  * Get generic flow operations structure from a port.
  *
  * @param port_id
