diff --git a/configure.in b/configure.in
index dec0fea3..74439433 100644
--- a/configure.in
+++ b/configure.in
@@ -66,6 +66,13 @@ AC_CHECK_DECLS(PTRACE_POKEDATA, [], [],
 #endif
 #include <sys/ptrace.h>
 ])
+AC_CHECK_DECLS(PTRACE_CONT, [], [],
+[$ac_includes_default
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#include <sys/ptrace.h>
+])
 AC_CHECK_DECLS(PT_IO, [], [],
 [$ac_includes_default
 #if HAVE_SYS_TYPES_H
@@ -87,6 +94,13 @@ AC_CHECK_DECLS(PT_GETFPREGS, [], [],
 #endif
 #include <sys/ptrace.h>
 ])
+AC_CHECK_DECLS(PT_CONTINUE, [], [],
+[$ac_includes_default
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#include <sys/ptrace.h>
+])
 
 dnl Checks for library functions.
 AC_FUNC_MEMCMP
diff --git a/src/ptrace/_UPT_resume.c b/src/ptrace/_UPT_resume.c
index 11242e8d..f419fed3 100644
--- a/src/ptrace/_UPT_resume.c
+++ b/src/ptrace/_UPT_resume.c
@@ -32,7 +32,9 @@ _UPT_resume (unw_addr_space_t as, unw_cursor_t *c, void *arg)
 
 #ifdef HAVE_TTRACE
 # warning No support for ttrace() yet.
-#else
+#elif HAVE_DECL_PTRACE_CONT
   return ptrace (PTRACE_CONT, ui->pid, 0, 0);
+#elif HAVE_DECL_PT_CONTINUE
+  return ptrace(PT_CONTINUE, ui->pid, (caddr_t)1, 0);
 #endif
 }