diff --git a/ChangeLog b/ChangeLog
index 27033ae..f3e3ba2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -182,6 +182,9 @@ caseless match, the "first code unit" optimization did not get the casing
 right, and the assertion failed to match a character in the other case if it
 did not start with the same code unit.
 
+39. Fixed the incorrect computation of jump sizes on x86 CPUs in JIT. A masking
+operation was incorrectly removed in r1136. Reported by Ralf Junker.
+
 
 Version 10.33 16-April-2019
 ---------------------------
diff --git a/src/pcre2_jit_test.c b/src/pcre2_jit_test.c
index 65f40bd..a9b3880 100644
--- a/src/pcre2_jit_test.c
+++ b/src/pcre2_jit_test.c
@@ -196,6 +196,8 @@ static struct regression_test_case regression_test_cases[] = {
 	{ CMUP, A, 0, 0, "\xf0\x90\x90\xa8{2}", "\xf0\x90\x90\x80#\xf0\x90\x90\xa8\xf0\x90\x90\x80" },
 	{ CMUP, A, 0, 0, "\xe1\xbd\xb8\xe1\xbf\xb8", "\xe1\xbf\xb8\xe1\xbd\xb8" },
 	{ M, A, 0, 0, "[3-57-9]", "5" },
+	{ PCRE2_AUTO_CALLOUT, A, 0, 0, "12345678901234567890123456789012345678901234567890123456789012345678901234567890",
+		"12345678901234567890123456789012345678901234567890123456789012345678901234567890" },
 
 	/* Assertions. */
 	{ MU, A, 0, 0, "\\b[^A]", "A_B#" },
diff --git a/src/sljit/sljitNativeX86_common.c b/src/sljit/sljitNativeX86_common.c
index 26e8475..6296da5 100644
--- a/src/sljit/sljitNativeX86_common.c
+++ b/src/sljit/sljitNativeX86_common.c
@@ -2515,6 +2515,7 @@ SLJIT_API_FUNC_ATTRIBUTE struct sljit_jump* sljit_emit_jump(struct sljit_compile
 	jump = (struct sljit_jump*)ensure_abuf(compiler, sizeof(struct sljit_jump));
 	PTR_FAIL_IF_NULL(jump);
 	set_jump(jump, compiler, (type & SLJIT_REWRITABLE_JUMP) | ((type & 0xff) << TYPE_SHIFT));
+	type &= 0xff;
 
 	/* Worst case size. */
 #if (defined SLJIT_CONFIG_X86_32 && SLJIT_CONFIG_X86_32)