diff --git a/doc/helper-guide/odp.dox b/doc/helper-guide/odp.dox
index ae341918e7..9442860026 100644
--- a/doc/helper-guide/odp.dox
+++ b/doc/helper-guide/odp.dox
@@ -16,6 +16,10 @@
  *
  *  @image html overview.svg
  *
+ * ODP must be initialized before calling helper functions, unless stated
+ * otherwise. Pre-processor macros may be invoked independently of ODP
+ * initialization.
+ *
  * @section contact Contact Details
  * - The main web site is http://www.opendataplane.org/
  * - The git repo is https://github.com/OpenDataPlane/odp.git
diff --git a/helper/include/odp/helper/eth.h b/helper/include/odp/helper/eth.h
index 2a1f3f159b..3ae16edb85 100644
--- a/helper/include/odp/helper/eth.h
+++ b/helper/include/odp/helper/eth.h
@@ -111,6 +111,8 @@ ODP_STATIC_ASSERT(sizeof(odph_vlanhdr_t) == ODPH_VLANHDR_LEN,
  * and may have leading zeros. String does not have to be NULL terminated.
  * The address is written only when successful.
  *
+ * This function may be called before ODP initialization.
+ *
  * @param[out] mac   Pointer to Ethernet address for output
  * @param      str   MAC address string to be parsed
  *
diff --git a/helper/include/odp/helper/ip.h b/helper/include/odp/helper/ip.h
index bbae401b24..be8e37d982 100644
--- a/helper/include/odp/helper/ip.h
+++ b/helper/include/odp/helper/ip.h
@@ -275,6 +275,8 @@ typedef struct ODP_PACKED {
  * NULL terminated. The address is written only when successful. The address
  * byte order is CPU native.
  *
+ * This function may be called before ODP initialization.
+ *
  * @param[out] ip_addr    Pointer to IPv4 address for output (in native endian)
  * @param      str        IPv4 address string to be parsed
  *
diff --git a/helper/include/odp/helper/odph_api.h b/helper/include/odp/helper/odph_api.h
index 2541efa89a..ebc737344d 100644
--- a/helper/include/odp/helper/odph_api.h
+++ b/helper/include/odp/helper/odph_api.h
@@ -7,6 +7,9 @@
  *
  * The OpenDataPlane helper API
  *
+ * ODP must be initialized before calling helper functions, unless stated
+ * otherwise. Pre-processor macros may be invoked independently of ODP
+ * initialization.
  */
 
 #ifndef ODP_HELPER_H_
diff --git a/helper/include/odp/helper/string.h b/helper/include/odp/helper/string.h
index 25096f0fdb..c3dc8b6a15 100644
--- a/helper/include/odp/helper/string.h
+++ b/helper/include/odp/helper/string.h
@@ -32,6 +32,8 @@ extern "C" {
  * terminated, unless sz is zero in which case returns dst without doing
  * anything else.
  *
+ * This function may be called before ODP initialization.
+ *
  * @param[out] dst Pointer to destination string.
  * @param src Pointer to source string.
  * @param sz Destination size.
diff --git a/helper/include/odp/helper/threads.h b/helper/include/odp/helper/threads.h
index ca420e80a3..04eab27cf7 100644
--- a/helper/include/odp/helper/threads.h
+++ b/helper/include/odp/helper/threads.h
@@ -347,6 +347,8 @@ int odph_odpthread_getaffinity(void);
  *                                                   pthreads are used instead.
  * </table>
  *
+ * This function may be called before ODP initialization.
+ *
  * @param argc   Argument count
  * @param argv   Argument vector
  *
@@ -361,6 +363,8 @@ int odph_parse_options(int argc, char *argv[]);
  * Return used ODP helper options. odph_parse_options() must be called before
  * using this function.
  *
+ * This function may be called before ODP initialization.
+ *
  * @param[out] options  ODP helper options
  *
  * @return 0 on success, -1 on failure
diff --git a/helper/include/odp/helper/version.h.in b/helper/include/odp/helper/version.h.in
index e576de561e..19bc64203b 100644
--- a/helper/include/odp/helper/version.h.in
+++ b/helper/include/odp/helper/version.h.in
@@ -57,6 +57,8 @@ extern "C" {
  *
  * The string is null terminated.
  *
+ * This function may be called before ODP initialization.
+ *
  * @return Pointer to helper library version string
  */
 const char *odph_version_str(void);