diff --git a/arch/arm/crtools.c b/arch/arm/crtools.c
index c1ee5dc1d..8428e15b8 100644
--- a/arch/arm/crtools.c
+++ b/arch/arm/crtools.c
@@ -47,6 +47,13 @@ void parasite_setup_regs(unsigned long new_ip, user_regs_struct_t *regs)
 	regs->ARM_cpsr &= PSR_f | PSR_s | PSR_x | PSR_T_BIT | MODE32_BIT;
 }
 
+int task_in_compat_mode(pid_t pid)
+{
+	/*
+	 * TODO: Add proper check here
+	 */
+	return 0;
+}
 
 int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 		unsigned long arg1,
diff --git a/arch/x86/crtools.c b/arch/x86/crtools.c
index 605979e7b..dcb8f55f0 100644
--- a/arch/x86/crtools.c
+++ b/arch/x86/crtools.c
@@ -45,6 +45,28 @@ void parasite_setup_regs(unsigned long new_ip, user_regs_struct_t *regs)
 	regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF | X86_EFLAGS_IF);
 }
 
+int task_in_compat_mode(pid_t pid)
+{
+	unsigned long cs, ds;
+
+	errno = 0;
+	cs = ptrace(PTRACE_PEEKUSER, pid, offsetof(user_regs_struct_t, cs), 0);
+	if (errno != 0) {
+		perror("Can't get CS register");
+		return -1;
+	}
+
+	errno = 0;
+	ds = ptrace(PTRACE_PEEKUSER, pid, offsetof(user_regs_struct_t, ds), 0);
+	if (errno != 0) {
+		perror("Can't get DS register");
+		return -1;
+	}
+
+	/* It's x86-32 or x32 */
+	return cs != 0x33 || ds == 0x2b;
+}
+
 int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 		unsigned long arg1,
 		unsigned long arg2,
diff --git a/include/parasite-syscall.h b/include/parasite-syscall.h
index 0c222fb54..2f32d03c6 100644
--- a/include/parasite-syscall.h
+++ b/include/parasite-syscall.h
@@ -71,5 +71,6 @@ int syscall_seized(struct parasite_ctl *ctl, int nr, unsigned long *ret,
 		unsigned long arg6);
 
 extern int __parasite_execute(struct parasite_ctl *ctl, pid_t pid, user_regs_struct_t *regs);
+extern int task_in_compat_mode(pid_t pid);
 
 #endif /* __CR_PARASITE_SYSCALL_H__ */
diff --git a/parasite-syscall.c b/parasite-syscall.c
index 0941c3912..c86307f8a 100644
--- a/parasite-syscall.c
+++ b/parasite-syscall.c
@@ -713,6 +713,11 @@ struct parasite_ctl *parasite_prep_ctl(pid_t pid, struct list_head *vma_area_lis
 	struct parasite_ctl *ctl = NULL;
 	struct vma_area *vma_area;
 
+	if (task_in_compat_mode(pid)) {
+		pr_err("Can't checkpoint task running in compat mode\n");
+		goto err;
+	}
+
 	/*
 	 * Control block early setup.
 	 */