diff --git a/ChangeLog b/ChangeLog
index 6359e33..2b7940f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -14,6 +14,8 @@ in pcre2grep with buffered fseek(stdin).
 3. Merged patch from @carenas (GitHub #37, acc520924) to fix tests when -S is 
 not supported.
 
+4. Revert an unintended change in JIT repeat detection.
+
 
 Version 10.39 29-October-2021
 -----------------------------
diff --git a/src/pcre2_jit_compile.c b/src/pcre2_jit_compile.c
index db2ce65..227714e 100644
--- a/src/pcre2_jit_compile.c
+++ b/src/pcre2_jit_compile.c
@@ -1621,7 +1621,7 @@ if (end[-(1 + LINK_SIZE)] != OP_KET || PRIVATE_DATA(begin) != 0)
 
 /* /(?:AB){4,6}/ is currently converted to /(?:AB){3}(?AB){1,3}/
  * Skip the check of the second part. */
-if (PRIVATE_DATA(end - LINK_SIZE) == 0)
+if (PRIVATE_DATA(end - LINK_SIZE) != 0)
   return TRUE;
 
 next = end;
diff --git a/src/pcre2_jit_test.c b/src/pcre2_jit_test.c
index 8dee16e..269ad4f 100644
--- a/src/pcre2_jit_test.c
+++ b/src/pcre2_jit_test.c
@@ -291,6 +291,7 @@ static struct regression_test_case regression_test_cases[] = {
 	{ MU, A, 0, 0, "(a(?:bc|cb|b|c)+?|ss)+e", "accssabccbcacbccbbXaccssabccbcacbccbbe" },
 	{ MU, A, 0, 0, "(a(?:bc|cb|b|c)+|ss)+?e", "accssabccbcacbccbbXaccssabccbcacbccbbe" },
 	{ MU, A, 0, 0, "(?:(b(c)+?)+)?\?(?:(bc)+|(cb)+)+(?:m)+", "bccbcccbcbccbcbPbccbcccbcbccbcbmmn" },
+	{ MU, A, 0, 0, "(aa|bb){8,1000}", "abaabbaabbaabbaab_aabbaabbaabbaabbaabbaabb_" },
 
 	/* Greedy and non-greedy * operators */
 	{ CMU, A, 0, 0, "(?:AA)*AB", "aaaaaaamaaaaaaab" },