diff --git a/Makefile b/Makefile
index c99361e719..03b800da0c 100644
--- a/Makefile
+++ b/Makefile
@@ -34,13 +34,8 @@ all::
 # library. Support for version 1 will likely be removed in some future
 # release of Git, as upstream has all but abandoned it.
 #
-# When using USE_LIBPCRE1, define NO_LIBPCRE1_JIT if the PCRE v1
-# library is compiled without --enable-jit. We will auto-detect
-# whether the version of the PCRE v1 library in use has JIT support at
-# all, but we unfortunately can't auto-detect whether JIT support
-# hasn't been compiled in in an otherwise JIT-supporting version. If
-# you have link-time errors about a missing `pcre_jit_exec` define
-# this, or recompile PCRE v1 with --enable-jit.
+# When using USE_LIBPCRE1, define NO_LIBPCRE1_JIT if you want to
+# disable JIT even if supported by your library.
 #
 # Define LIBPCREDIR=/foo/bar if your PCRE header and library files are
 # in /foo/bar/include and /foo/bar/lib directories. Which version of
diff --git a/grep.c b/grep.c
index 5d268b13d9..0bb4cbd3d8 100644
--- a/grep.c
+++ b/grep.c
@@ -374,6 +374,7 @@ static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 	const char *error;
 	int erroffset;
 	int options = PCRE_MULTILINE;
+	int study_options = 0;
 
 	if (opt->ignore_case) {
 		if (!opt->ignore_locale && has_non_ascii(p->pattern))
@@ -388,15 +389,18 @@ static void compile_pcre1_regexp(struct grep_pat *p, const struct grep_opt *opt)
 	if (!p->pcre1_regexp)
 		compile_regexp_failed(p, error);
 
-	p->pcre1_extra_info = pcre_study(p->pcre1_regexp, GIT_PCRE_STUDY_JIT_COMPILE, &error);
-	if (!p->pcre1_extra_info && error)
-		die("%s", error);
-
-#ifdef GIT_PCRE1_USE_JIT
+#if defined(PCRE_CONFIG_JIT) && !defined(NO_LIBPCRE1_JIT)
 	pcre_config(PCRE_CONFIG_JIT, &p->pcre1_jit_on);
 	if (opt->debug)
 		fprintf(stderr, "pcre1_jit_on=%d\n", p->pcre1_jit_on);
+
+	if (p->pcre1_jit_on)
+		study_options = PCRE_STUDY_JIT_COMPILE;
 #endif
+
+	p->pcre1_extra_info = pcre_study(p->pcre1_regexp, study_options, &error);
+	if (!p->pcre1_extra_info && error)
+		die("%s", error);
 }
 
 static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
@@ -425,7 +429,7 @@ static int pcre1match(struct grep_pat *p, const char *line, const char *eol,
 static void free_pcre1_regexp(struct grep_pat *p)
 {
 	pcre_free(p->pcre1_regexp);
-#ifdef GIT_PCRE1_USE_JIT
+#ifdef PCRE_CONFIG_JIT
 	if (p->pcre1_jit_on)
 		pcre_free_study(p->pcre1_extra_info);
 	else
diff --git a/grep.h b/grep.h
index 1060f0fe50..05dc1bb98e 100644
--- a/grep.h
+++ b/grep.h
@@ -6,17 +6,6 @@
 #ifndef PCRE_NO_UTF8_CHECK
 #define PCRE_NO_UTF8_CHECK 0
 #endif
-#ifdef PCRE_CONFIG_JIT
-#if PCRE_MAJOR >= 8 && PCRE_MINOR >= 32
-#ifndef NO_LIBPCRE1_JIT
-#define GIT_PCRE1_USE_JIT
-#define GIT_PCRE_STUDY_JIT_COMPILE PCRE_STUDY_JIT_COMPILE
-#endif
-#endif
-#endif
-#ifndef GIT_PCRE_STUDY_JIT_COMPILE
-#define GIT_PCRE_STUDY_JIT_COMPILE 0
-#endif
 #else
 typedef int pcre;
 typedef int pcre_extra;