diff --git a/src/pcre2_match_next.c b/src/pcre2_match_next.c
index ae5a12ab5..9feb82252 100644
--- a/src/pcre2_match_next.c
+++ b/src/pcre2_match_next.c
@@ -95,6 +95,12 @@ do_bumpalong(pcre2_match_data *match_data, PCRE2_SIZE offset)
 PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
 pcre2_next_match(pcre2_match_data *match_data, PCRE2_SIZE *pstart_offset, uint32_t *poptions)
 {
+  /* Preconditions on argument values */
+
+  PCRE2_ASSERT(match_data != NULL);
+  PCRE2_ASSERT(pstart_offset != NULL);
+  PCRE2_ASSERT(poptions != NULL);
+
   PCRE2_SIZE start_offset = match_data->start_offset;
   PCRE2_SIZE *ovector = match_data->ovector;
 
@@ -105,6 +111,10 @@ pcre2_next_match(pcre2_match_data *match_data, PCRE2_SIZE *pstart_offset, uint32
   if (match_data->rc < 0)
     return FALSE;
 
+  /* Preconditions on argument state */
+
+  PCRE2_ASSERT(match_data->code != NULL);
+
   /* Match succeeded: get the start offset for the next match */
 
   /* Although \K can affect the position of ovector[0], there are no ways to do