diff --git a/fsw/src/cf_cfdp.c b/fsw/src/cf_cfdp.c
index c79fa8d3..7e4c0376 100644
--- a/fsw/src/cf_cfdp.c
+++ b/fsw/src/cf_cfdp.c
@@ -299,22 +299,6 @@ CF_Logical_PduBuffer_t *CF_CFDP_ConstructPduHeader(const CF_Transaction_t *txn,
     return ph;
 }
 
-/*----------------------------------------------------------------
- *
- * Internal helper routine only, not part of API.
- *
- *-----------------------------------------------------------------*/
-static inline size_t CF_strnlen(const char *str, size_t maxlen)
-{
-    const char *end = memchr(str, 0, maxlen);
-    if (end != NULL)
-    {
-        /* actual length of string is difference */
-        maxlen = end - str;
-    }
-    return maxlen;
-}
-
 /*----------------------------------------------------------------
  *
  * Application-scope internal function
diff --git a/fsw/src/cf_utils.c b/fsw/src/cf_utils.c
index 4b35c9b6..715dd4de 100644
--- a/fsw/src/cf_utils.c
+++ b/fsw/src/cf_utils.c
@@ -196,8 +196,7 @@ CFE_Status_t CF_WriteHistoryEntryToFile(osal_id_t fd, const CF_History_t *histor
                 snprintf(linebuf, sizeof(linebuf), "DST: %s\n", history->fnames.dst_filename);
                 break;
         }
-
-        len = strlen(linebuf);
+        len = CF_strnlen(linebuf, (CF_FILENAME_MAX_LEN * 2) + 128);
         ret = CF_WrappedWrite(fd, linebuf, len);
         if (ret != len)
         {
@@ -588,3 +587,22 @@ CF_TxnStatus_t CF_TxnStatus_From_ConditionCode(CF_CFDP_ConditionCode_t cc)
     /* All CFDP CC values directly correspond to a Transaction Status of the same numeric value */
     return (CF_TxnStatus_t)cc;
 }
+
+/*----------------------------------------------------------------
+ *
+ * Function: CF_strnlen
+ *
+ * Application-scope internal function
+ * See description in cf_utils.h for argument/return detail
+ *
+ *-----------------------------------------------------------------*/
+size_t CF_strnlen(const char *str, size_t maxlen)
+{
+    const char *end = memchr(str, 0, maxlen);
+    if (end != NULL)
+    {
+        /* actual length of string is difference */
+        maxlen = end - str;
+    }
+    return maxlen;
+}
\ No newline at end of file
diff --git a/fsw/src/cf_utils.h b/fsw/src/cf_utils.h
index fd839ce0..81f833fd 100644
--- a/fsw/src/cf_utils.h
+++ b/fsw/src/cf_utils.h
@@ -518,4 +518,21 @@ CF_TxnStatus_t CF_TxnStatus_From_ConditionCode(CF_CFDP_ConditionCode_t cc);
  */
 bool CF_TxnStatus_IsError(CF_TxnStatus_t txn_stat);
 
+/************************************************************************/
+/** @brief Calculates the length of a string up to a maximum length
+ *
+ * Purpose: Provides a local OSAL routine to get the functionality
+ *          of the (non-C99) "strnlen()" function, via the
+ *          C89/C99 standard "memchr()" function instead.
+ *
+ * @par Assumptions, External Events, and Notes:
+ *       None
+ *
+ * @param str     Pointer to the input string
+ * @param maxlen  Maximum number of characters to check
+ *
+ * @returns Length of the string up to `maxlen` characters
+ */
+size_t CF_strnlen(const char *str, size_t maxlen);
+
 #endif /* !CF_UTILS_H */