diff --git a/nsprpub/pr/include/md/_netbsd.h b/nsprpub/pr/include/md/_netbsd.h
index 126e01f5be82..6065f3705645 100644
--- a/nsprpub/pr/include/md/_netbsd.h
+++ b/nsprpub/pr/include/md/_netbsd.h
@@ -63,8 +63,15 @@
 #elif defined(__alpha__)
 #define JB_SP_INDEX 34
 #elif defined(__arm32__)
+/*
+ * On the arm32, the jmpbuf regs underwent a name change after NetBSD 1.3.
+ */
+#ifdef JMPBUF_REG_R13
 #define JB_SP_INDEX JMPBUF_REG_R13
 #else
+#define JB_SP_INDEX _JB_REG_R13
+#endif
+#else
 #error "Need to define SP index in jmp_buf here"
 #endif
 #define _MD_GET_SP(_th)    (_th)->md.context[JB_SP_INDEX]