diff --git a/grep.h b/grep.h
index 3b948d9..ce90969 100644
--- a/grep.h
+++ b/grep.h
@@ -11,6 +11,9 @@
 #ifndef PCRE_STUDY_JIT_COMPILE
 #define PCRE_STUDY_JIT_COMPILE 0
 #endif
+#if PCRE_MAJOR <= 8 && PCRE_MINOR < 20
+typedef int pcre_jit_stack;
+#endif
 #else
 typedef int pcre;
 typedef int pcre_extra;