diff --git a/src/kernel_abi.h b/src/kernel_abi.h
index 3aa3180c5ac..5df30a875f3 100644
--- a/src/kernel_abi.h
+++ b/src/kernel_abi.h
@@ -2056,7 +2056,7 @@ struct X64Arch : public BaseArch<SupportedArch::x86_64, WordSize64Defs> {
     ptr<struct ucontext> uc_link;
     stack_t	             uc_stack;
     struct sigcontext    uc_mcontext;
-    kernel_sigset_t	    uc_sigmask;
+    kernel_sigset_t	     uc_sigmask;
   };
 
   struct rt_sigframe {
@@ -2290,17 +2290,20 @@ struct X86Arch : public BaseArch<SupportedArch::x86, WordSize32Defs> {
   RR_VERIFY_TYPE_ARCH(SupportedArch::x86, ::sigcontext, sigcontext);
 
   struct ucontext {
-    unsigned int	  uc_flags;
-    unsigned int 	  uc_link;
-    stack_t	  uc_stack;
-    struct sigcontext uc_mcontext;
-    kernel_sigset_t	  uc_sigmask;
+    unsigned_long	       uc_flags;
+    ptr<struct ucontext> uc_link;
+    stack_t	             uc_stack;
+    struct sigcontext    uc_mcontext;
+    kernel_sigset_t	     uc_sigmask;
   };
 
   struct rt_sigframe {
     ptr<char> pretcode;
-    struct ucontext uc;
+    int sig;
+    uint32_t pinfo;
+    uint32_t puc;
     siginfo_t info;
+    struct ucontext uc;
     // Extended ISA state follows
   };