diff --git a/src/cmd/cc/godefs.c b/src/cmd/cc/godefs.c
index 1f2a9d7e04..d3ab52fde4 100644
--- a/src/cmd/cc/godefs.c
+++ b/src/cmd/cc/godefs.c
@@ -317,9 +317,9 @@ godefvar(Sym *s)
 	switch(t->etype) {
 	case TENUM:
 		if(!typefd[t->etype])
-			Bprint(&outbuf, "const %U = %lld\n", s->name, s->vconst);
+			Bprint(&outbuf, "const %s = %lld\n", s->name, s->vconst);
 		else
-			Bprint(&outbuf, "const %U = %f\n;", s->name, s->fconst);
+			Bprint(&outbuf, "const %s = %f\n;", s->name, s->fconst);
 		break;
 
 	case TFUNC:
diff --git a/src/cmd/dist/buildruntime.c b/src/cmd/dist/buildruntime.c
index 5daa31494b..2396e20c56 100644
--- a/src/cmd/dist/buildruntime.c
+++ b/src/cmd/dist/buildruntime.c
@@ -346,6 +346,10 @@ mkzruntimedefs(char *dir, char *file)
 		"\n"
 	);
 
+	// Do not emit constant definitions for these.
+	vadd(&seen, "true");
+	vadd(&seen, "false");
+	vadd(&seen, "raceenabled");
 	
 	// Run 6c -D GOOS_goos -D GOARCH_goarch -I workdir -q -n -o workdir/runtimedefs
 	// on each of the runtimedefs C files.
@@ -375,15 +379,15 @@ mkzruntimedefs(char *dir, char *file)
 	splitlines(&lines, bstr(&in));
 	for(i=0; i<lines.len; i++) {
 		p = lines.p[i];
-		// Drop comment, func, and const lines.
-		if(hasprefix(p, "//") || hasprefix(p, "const") || hasprefix(p, "func"))
+		// Drop comment and func lines.
+		if(hasprefix(p, "//") || hasprefix(p, "func"))
 			continue;
 		
 		// Note beginning of type or var decl, which can be multiline.
 		// Remove duplicates.  The linear check of seen here makes the
 		// whole processing quadratic in aggregate, but there are only
 		// about 100 declarations, so this is okay (and simple).
-		if(hasprefix(p, "type ") || hasprefix(p, "var ")) {
+		if(hasprefix(p, "type ") || hasprefix(p, "var ") || hasprefix(p, "const ")) {
 			splitfields(&fields, p);
 			if(fields.len < 2)
 				continue;
@@ -394,6 +398,17 @@ mkzruntimedefs(char *dir, char *file)
 			}
 			vadd(&seen, fields.p[1]);
 		}
+
+		// Const lines are printed in original case (usually upper). Add a leading _ as needed.
+		if(hasprefix(p, "const ")) {
+			if('A' <= p[6] && p[6] <= 'Z')
+				bwritestr(&out, "const _");
+			else
+				bwritestr(&out, "const ");
+			bwritestr(&out, p+6);
+			continue;
+		}
+
 		if(skip) {
 			if(hasprefix(p, "}"))
 				skip = 0;
diff --git a/src/pkg/runtime/defs.c b/src/pkg/runtime/defs.c
index 7563344578..b6ed9c8115 100644
--- a/src/pkg/runtime/defs.c
+++ b/src/pkg/runtime/defs.c
@@ -12,3 +12,4 @@
 #include "race.h"
 #include "chan.h"
 #include "mprof.h"
+#include "defs_GOOS_GOARCH.h"
diff --git a/src/pkg/runtime/defs_darwin_386.h b/src/pkg/runtime/defs_darwin_386.h
index 7b210eebf8..0e0b4fbf79 100644
--- a/src/pkg/runtime/defs_darwin_386.h
+++ b/src/pkg/runtime/defs_darwin_386.h
@@ -124,7 +124,7 @@ typedef struct MachHeader MachHeader;
 typedef struct MachNDR MachNDR;
 typedef struct MachPort MachPort;
 typedef struct StackT StackT;
-typedef struct Sigaction Sigaction;
+typedef struct SigactionT SigactionT;
 typedef struct Siginfo Siginfo;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
@@ -142,7 +142,7 @@ typedef struct FloatState32 FloatState32;
 typedef struct ExceptionState32 ExceptionState32;
 typedef struct Mcontext32 Mcontext32;
 typedef struct Ucontext Ucontext;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -182,7 +182,7 @@ struct StackT {
 };
 typedef	byte	Sighandler[4];
 
-struct Sigaction {
+struct SigactionT {
 	byte	__sigaction_u[4];
 	void	*sa_tramp;
 	uint32	sa_mask;
@@ -379,7 +379,7 @@ struct Ucontext {
 	Mcontext32	*uc_mcontext;
 };
 
-struct Kevent {
+struct KeventT {
 	uint32	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_darwin_amd64.h b/src/pkg/runtime/defs_darwin_amd64.h
index 2d464a9e50..4bf83c1cb9 100644
--- a/src/pkg/runtime/defs_darwin_amd64.h
+++ b/src/pkg/runtime/defs_darwin_amd64.h
@@ -124,7 +124,7 @@ typedef struct MachHeader MachHeader;
 typedef struct MachNDR MachNDR;
 typedef struct MachPort MachPort;
 typedef struct StackT StackT;
-typedef struct Sigaction Sigaction;
+typedef struct SigactionT SigactionT;
 typedef struct Siginfo Siginfo;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
@@ -142,7 +142,7 @@ typedef struct FloatState32 FloatState32;
 typedef struct ExceptionState32 ExceptionState32;
 typedef struct Mcontext32 Mcontext32;
 typedef struct Ucontext Ucontext;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -183,7 +183,7 @@ struct StackT {
 };
 typedef	byte	Sighandler[8];
 
-struct Sigaction {
+struct SigactionT {
 	byte	__sigaction_u[8];
 	void	*sa_tramp;
 	uint32	sa_mask;
@@ -382,7 +382,7 @@ struct Ucontext {
 	Mcontext64	*uc_mcontext;
 };
 
-struct Kevent {
+struct KeventT {
 	uint64	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_dragonfly_386.h b/src/pkg/runtime/defs_dragonfly_386.h
index 696dcd887d..032b23574e 100644
--- a/src/pkg/runtime/defs_dragonfly_386.h
+++ b/src/pkg/runtime/defs_dragonfly_386.h
@@ -94,7 +94,7 @@ typedef struct Ucontext Ucontext;
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -185,7 +185,7 @@ struct Itimerval {
 	Timeval	it_value;
 };
 
-struct Kevent {
+struct KeventT {
 	uint32	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_dragonfly_amd64.h b/src/pkg/runtime/defs_dragonfly_amd64.h
index 74581cc94c..c37a72e729 100644
--- a/src/pkg/runtime/defs_dragonfly_amd64.h
+++ b/src/pkg/runtime/defs_dragonfly_amd64.h
@@ -94,7 +94,7 @@ typedef struct Ucontext Ucontext;
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -195,7 +195,7 @@ struct Itimerval {
 	Timeval	it_value;
 };
 
-struct Kevent {
+struct KeventT {
 	uint64	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_freebsd_386.h b/src/pkg/runtime/defs_freebsd_386.h
index fab9385269..e625079bc7 100644
--- a/src/pkg/runtime/defs_freebsd_386.h
+++ b/src/pkg/runtime/defs_freebsd_386.h
@@ -98,7 +98,7 @@ typedef struct Ucontext Ucontext;
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -200,7 +200,7 @@ struct Itimerval {
 	Timeval	it_value;
 };
 
-struct Kevent {
+struct KeventT {
 	uint32	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_freebsd_amd64.h b/src/pkg/runtime/defs_freebsd_amd64.h
index c1db91803e..40476f9e4f 100644
--- a/src/pkg/runtime/defs_freebsd_amd64.h
+++ b/src/pkg/runtime/defs_freebsd_amd64.h
@@ -98,7 +98,7 @@ typedef struct Ucontext Ucontext;
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -211,7 +211,7 @@ struct Itimerval {
 	Timeval	it_value;
 };
 
-struct Kevent {
+struct KeventT {
 	uint64	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_freebsd_arm.h b/src/pkg/runtime/defs_freebsd_arm.h
index 4fc452e457..927d3a48b5 100644
--- a/src/pkg/runtime/defs_freebsd_arm.h
+++ b/src/pkg/runtime/defs_freebsd_arm.h
@@ -98,7 +98,7 @@ typedef struct Ucontext Ucontext;
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -173,7 +173,7 @@ struct Itimerval {
 	Timeval	it_value;
 };
 
-struct Kevent {
+struct KeventT {
 	uint32	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_linux_386.h b/src/pkg/runtime/defs_linux_386.h
index 27dae9e82b..2df3f66d80 100644
--- a/src/pkg/runtime/defs_linux_386.h
+++ b/src/pkg/runtime/defs_linux_386.h
@@ -95,7 +95,7 @@ typedef struct Xmmreg Xmmreg;
 typedef struct Fpstate Fpstate;
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
-typedef struct Sigaction Sigaction;
+typedef struct SigactionT SigactionT;
 typedef struct Siginfo Siginfo;
 typedef struct Sigaltstack Sigaltstack;
 typedef struct Sigcontext Sigcontext;
@@ -144,7 +144,7 @@ struct Timeval {
 	int32	tv_sec;
 	int32	tv_usec;
 };
-struct Sigaction {
+struct SigactionT {
 	void	*k_sa_handler;
 	uint32	sa_flags;
 	void	*sa_restorer;
diff --git a/src/pkg/runtime/defs_linux_amd64.h b/src/pkg/runtime/defs_linux_amd64.h
index 3e87df68a1..42826c39ee 100644
--- a/src/pkg/runtime/defs_linux_amd64.h
+++ b/src/pkg/runtime/defs_linux_amd64.h
@@ -88,7 +88,7 @@ enum {
 
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
-typedef struct Sigaction Sigaction;
+typedef struct SigactionT SigactionT;
 typedef struct Siginfo Siginfo;
 typedef struct Itimerval Itimerval;
 typedef struct EpollEvent EpollEvent;
@@ -103,7 +103,7 @@ struct Timeval {
 	int64	tv_sec;
 	int64	tv_usec;
 };
-struct Sigaction {
+struct SigactionT {
 	void	*sa_handler;
 	uint64	sa_flags;
 	void	*sa_restorer;
diff --git a/src/pkg/runtime/defs_linux_arm.h b/src/pkg/runtime/defs_linux_arm.h
index 05a17af64b..8c17e3805b 100644
--- a/src/pkg/runtime/defs_linux_arm.h
+++ b/src/pkg/runtime/defs_linux_arm.h
@@ -151,8 +151,8 @@ struct Siginfo {
 	uint8 _sifields[4];
 };
 
-typedef struct Sigaction Sigaction;
-struct Sigaction {
+typedef struct SigactionT SigactionT;
+struct SigactionT {
 	void *sa_handler;
 	uint32 sa_flags;
 	void *sa_restorer;
diff --git a/src/pkg/runtime/defs_netbsd_386.h b/src/pkg/runtime/defs_netbsd_386.h
index 7fd66959f3..fb23611990 100644
--- a/src/pkg/runtime/defs_netbsd_386.h
+++ b/src/pkg/runtime/defs_netbsd_386.h
@@ -91,7 +91,7 @@ typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
 typedef struct McontextT McontextT;
 typedef struct UcontextT UcontextT;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -143,7 +143,7 @@ struct UcontextT {
 	int32	__uc_pad[4];
 };
 
-struct Kevent {
+struct KeventT {
 	uint32	ident;
 	uint32	filter;
 	uint32	flags;
diff --git a/src/pkg/runtime/defs_netbsd_amd64.h b/src/pkg/runtime/defs_netbsd_amd64.h
index 972af165b7..f6ba3db189 100644
--- a/src/pkg/runtime/defs_netbsd_amd64.h
+++ b/src/pkg/runtime/defs_netbsd_amd64.h
@@ -91,7 +91,7 @@ typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
 typedef struct McontextT McontextT;
 typedef struct UcontextT UcontextT;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -147,7 +147,7 @@ struct UcontextT {
 	McontextT	uc_mcontext;
 };
 
-struct Kevent {
+struct KeventT {
 	uint64	ident;
 	uint32	filter;
 	uint32	flags;
diff --git a/src/pkg/runtime/defs_netbsd_arm.h b/src/pkg/runtime/defs_netbsd_arm.h
index c6f5b1c47c..815d54749b 100644
--- a/src/pkg/runtime/defs_netbsd_arm.h
+++ b/src/pkg/runtime/defs_netbsd_arm.h
@@ -91,7 +91,7 @@ typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
 typedef struct McontextT McontextT;
 typedef struct UcontextT UcontextT;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -147,7 +147,7 @@ struct UcontextT {
 	int32	__uc_pad[2];
 };
 
-struct Kevent {
+struct KeventT {
 	uint32	ident;
 	uint32	filter;
 	uint32	flags;
diff --git a/src/pkg/runtime/defs_openbsd_386.h b/src/pkg/runtime/defs_openbsd_386.h
index b8f993e2b8..a63b182a04 100644
--- a/src/pkg/runtime/defs_openbsd_386.h
+++ b/src/pkg/runtime/defs_openbsd_386.h
@@ -89,7 +89,7 @@ typedef struct StackT StackT;
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -155,7 +155,7 @@ struct Itimerval {
 	Timeval	it_value;
 };
 
-struct Kevent {
+struct KeventT {
 	uint32	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_openbsd_amd64.h b/src/pkg/runtime/defs_openbsd_amd64.h
index a1ae2ef65c..818ac35207 100644
--- a/src/pkg/runtime/defs_openbsd_amd64.h
+++ b/src/pkg/runtime/defs_openbsd_amd64.h
@@ -89,7 +89,7 @@ typedef struct StackT StackT;
 typedef struct Timespec Timespec;
 typedef struct Timeval Timeval;
 typedef struct Itimerval Itimerval;
-typedef struct Kevent Kevent;
+typedef struct KeventT KeventT;
 
 #pragma pack on
 
@@ -166,7 +166,7 @@ struct Itimerval {
 	Timeval	it_value;
 };
 
-struct Kevent {
+struct KeventT {
 	uint64	ident;
 	int16	filter;
 	uint16	flags;
diff --git a/src/pkg/runtime/defs_solaris_amd64.h b/src/pkg/runtime/defs_solaris_amd64.h
index 799724fadc..08727b017e 100644
--- a/src/pkg/runtime/defs_solaris_amd64.h
+++ b/src/pkg/runtime/defs_solaris_amd64.h
@@ -105,7 +105,7 @@ typedef struct Sigaltstack Sigaltstack;
 typedef struct Sigset Sigset;
 typedef struct StackT StackT;
 typedef struct Siginfo Siginfo;
-typedef struct Sigaction Sigaction;
+typedef struct SigactionT SigactionT;
 typedef struct Fpregset Fpregset;
 typedef struct Mcontext Mcontext;
 typedef struct Ucontext Ucontext;
@@ -149,7 +149,7 @@ struct Siginfo {
 	int32	si_pad;
 	byte	__data[240];
 };
-struct Sigaction {
+struct SigactionT {
 	int32	sa_flags;
 	byte	Pad_cgo_0[4];
 	byte	_funcptr[8];
diff --git a/src/pkg/runtime/malloc.go b/src/pkg/runtime/malloc.go
index e95bdbbf97..49afc67364 100644
--- a/src/pkg/runtime/malloc.go
+++ b/src/pkg/runtime/malloc.go
@@ -22,15 +22,13 @@ const (
 	pageSize  = 1 << pageShift
 	pageMask  = pageSize - 1
 
-	gcBits             = 4
-	wordsPerBitmapByte = 8 / gcBits
-	bitsPerPointer     = 2
-	bitsMask           = 1<<bitsPerPointer - 1
-	pointersPerByte    = 8 / bitsPerPointer
-	bitPtrMask         = bitsMask << 2
-	maxGCMask          = 64
-	bitsDead           = 0
-	bitsPointer        = 2
+	bitsPerPointer  = 2
+	bitsMask        = 1<<bitsPerPointer - 1
+	pointersPerByte = 8 / bitsPerPointer
+	bitPtrMask      = bitsMask << 2
+	maxGCMask       = 64
+	bitsDead        = 0
+	bitsPointer     = 2
 
 	bitBoundary = 1
 	bitMarked   = 2
diff --git a/src/pkg/runtime/netpoll_kqueue.c b/src/pkg/runtime/netpoll_kqueue.c
index 171346cce2..6b7fc869d3 100644
--- a/src/pkg/runtime/netpoll_kqueue.c
+++ b/src/pkg/runtime/netpoll_kqueue.c
@@ -11,7 +11,7 @@
 // Integrated network poller (kqueue-based implementation).
 
 int32	runtime·kqueue(void);
-int32	runtime·kevent(int32, Kevent*, int32, Kevent*, int32, Timespec*);
+int32	runtime·kevent(int32, KeventT*, int32, KeventT*, int32, Timespec*);
 void	runtime·closeonexec(int32);
 
 static int32 kq = -1;
@@ -30,7 +30,7 @@ runtime·netpollinit(void)
 int32
 runtime·netpollopen(uintptr fd, PollDesc *pd)
 {
-	Kevent ev[2];
+	KeventT ev[2];
 	int32 n;
 
 	// Arm both EVFILT_READ and EVFILT_WRITE in edge-triggered mode (EV_CLEAR)
@@ -72,7 +72,7 @@ G*
 runtime·netpoll(bool block)
 {
 	static int32 lasterr;
-	Kevent events[64], *ev;
+	KeventT events[64], *ev;
 	Timespec ts, *tp;
 	int32 n, i, mode;
 	G *gp;
diff --git a/src/pkg/runtime/os_darwin.c b/src/pkg/runtime/os_darwin.c
index c660fb8c10..bf13cdbafe 100644
--- a/src/pkg/runtime/os_darwin.c
+++ b/src/pkg/runtime/os_darwin.c
@@ -488,7 +488,7 @@ runtime·memlimit(void)
 void
 runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 {
-	Sigaction sa;
+	SigactionT sa;
 		
 	runtime·memclr((byte*)&sa, sizeof sa);
 	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
@@ -503,7 +503,7 @@ runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 GoSighandler*
 runtime·getsig(int32 i)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	runtime·sigaction(i, nil, &sa);
diff --git a/src/pkg/runtime/os_darwin.h b/src/pkg/runtime/os_darwin.h
index 91a405f214..af9052e9c2 100644
--- a/src/pkg/runtime/os_darwin.h
+++ b/src/pkg/runtime/os_darwin.h
@@ -25,8 +25,8 @@ typedef uint32 Sigset;
 void	runtime·sigprocmask(int32, Sigset*, Sigset*);
 void	runtime·unblocksignals(void);
 
-struct Sigaction;
-void	runtime·sigaction(uintptr, struct Sigaction*, struct Sigaction*);
+struct SigactionT;
+void	runtime·sigaction(uintptr, struct SigactionT*, struct SigactionT*);
 
 struct StackT;
 void	runtime·sigaltstack(struct StackT*, struct StackT*);
diff --git a/src/pkg/runtime/os_dragonfly.c b/src/pkg/runtime/os_dragonfly.c
index 65121d3273..a2a88e4c80 100644
--- a/src/pkg/runtime/os_dragonfly.c
+++ b/src/pkg/runtime/os_dragonfly.c
@@ -240,12 +240,12 @@ typedef struct sigaction {
 	} __sigaction_u;		/* signal handler */
 	int32	sa_flags;		/* see signal options below */
 	Sigset	sa_mask;		/* signal mask to apply */
-} Sigaction;
+} SigactionT;
 
 void
 runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
@@ -264,7 +264,7 @@ runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 GoSighandler*
 runtime·getsig(int32 i)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	runtime·sigaction(i, nil, &sa);
diff --git a/src/pkg/runtime/os_freebsd.c b/src/pkg/runtime/os_freebsd.c
index d360f6712d..ae959d90bb 100644
--- a/src/pkg/runtime/os_freebsd.c
+++ b/src/pkg/runtime/os_freebsd.c
@@ -248,12 +248,12 @@ typedef struct sigaction {
 	} __sigaction_u;		/* signal handler */
 	int32	sa_flags;		/* see signal options below */
 	Sigset	sa_mask;		/* signal mask to apply */
-} Sigaction;
+} SigactionT;
 
 void
 runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
@@ -272,7 +272,7 @@ runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 GoSighandler*
 runtime·getsig(int32 i)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	runtime·sigaction(i, nil, &sa);
diff --git a/src/pkg/runtime/os_linux.c b/src/pkg/runtime/os_linux.c
index 33c7563743..d3677f2e6c 100644
--- a/src/pkg/runtime/os_linux.c
+++ b/src/pkg/runtime/os_linux.c
@@ -293,7 +293,7 @@ extern void runtime·sigreturn(void);	// calls rt_sigreturn, only used with SA_R
 void
 runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	sa.sa_flags = SA_ONSTACK | SA_SIGINFO | SA_RESTORER;
@@ -319,7 +319,7 @@ runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 GoSighandler*
 runtime·getsig(int32 i)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	if(runtime·rt_sigaction(i, nil, &sa, sizeof(sa.sa_mask)) != 0)
diff --git a/src/pkg/runtime/os_linux.h b/src/pkg/runtime/os_linux.h
index d4b1902c3a..84f516d50c 100644
--- a/src/pkg/runtime/os_linux.h
+++ b/src/pkg/runtime/os_linux.h
@@ -8,8 +8,8 @@
 int32	runtime·futex(uint32*, int32, uint32, Timespec*, uint32*, uint32);
 int32	runtime·clone(int32, void*, M*, G*, void(*)(void));
 
-struct Sigaction;
-int32	runtime·rt_sigaction(uintptr, struct Sigaction*, void*, uintptr);
+struct SigactionT;
+int32	runtime·rt_sigaction(uintptr, struct SigactionT*, void*, uintptr);
 
 void	runtime·sigaltstack(Sigaltstack*, Sigaltstack*);
 void	runtime·sigpanic(void);
diff --git a/src/pkg/runtime/os_netbsd.c b/src/pkg/runtime/os_netbsd.c
index 0889181a81..8567146ed4 100644
--- a/src/pkg/runtime/os_netbsd.c
+++ b/src/pkg/runtime/os_netbsd.c
@@ -286,12 +286,12 @@ typedef struct sigaction {
 	} _sa_u;			/* signal handler */
 	uint32	sa_mask[4];		/* signal mask to apply */
 	int32	sa_flags;		/* see signal options below */
-} Sigaction;
+} SigactionT;
 
 void
 runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
@@ -310,7 +310,7 @@ runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 GoSighandler*
 runtime·getsig(int32 i)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	runtime·sigaction(i, nil, &sa);
diff --git a/src/pkg/runtime/os_openbsd.c b/src/pkg/runtime/os_openbsd.c
index 60db7efdd9..a746385314 100644
--- a/src/pkg/runtime/os_openbsd.c
+++ b/src/pkg/runtime/os_openbsd.c
@@ -263,12 +263,12 @@ typedef struct sigaction {
 	} __sigaction_u;		/* signal handler */
 	uint32	sa_mask;		/* signal mask to apply */
 	int32	sa_flags;		/* see signal options below */
-} Sigaction;
+} SigactionT;
 
 void
 runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
@@ -284,7 +284,7 @@ runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 GoSighandler*
 runtime·getsig(int32 i)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	runtime·sigaction(i, nil, &sa);
diff --git a/src/pkg/runtime/os_solaris.c b/src/pkg/runtime/os_solaris.c
index 0cdfd52c9b..42295aa754 100644
--- a/src/pkg/runtime/os_solaris.c
+++ b/src/pkg/runtime/os_solaris.c
@@ -267,7 +267,7 @@ extern void runtime·sigtramp(void);
 void
 runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
@@ -286,7 +286,7 @@ runtime·setsig(int32 i, GoSighandler *fn, bool restart)
 GoSighandler*
 runtime·getsig(int32 i)
 {
-	Sigaction sa;
+	SigactionT sa;
 
 	runtime·memclr((byte*)&sa, sizeof sa);
 	runtime·sigaction(i, nil, &sa);
@@ -530,7 +530,7 @@ runtime·setitimer(int32 which, Itimerval* value, Itimerval* ovalue)
 }
 
 /* int32 */ void
-runtime·sigaction(int32 sig, struct Sigaction* act, struct Sigaction* oact)
+runtime·sigaction(int32 sig, struct SigactionT* act, struct SigactionT* oact)
 {
 	runtime·sysvicall3(libc·sigaction, (uintptr)sig, (uintptr)act, (uintptr)oact);
 }
diff --git a/src/pkg/runtime/os_solaris.h b/src/pkg/runtime/os_solaris.h
index 355cdf5589..20a0027205 100644
--- a/src/pkg/runtime/os_solaris.h
+++ b/src/pkg/runtime/os_solaris.h
@@ -15,7 +15,7 @@ struct sigaction;
 void	runtime·sigpanic(void);
 
 void	runtime·setitimer(int32, Itimerval*, Itimerval*);
-void	runtime·sigaction(int32, struct Sigaction*, struct Sigaction*);
+void	runtime·sigaction(int32, struct SigactionT*, struct SigactionT*);
 void	runtime·sigaltstack(Sigaltstack*, Sigaltstack*);
 void	runtime·sigprocmask(int32, Sigset*, Sigset*);
 void	runtime·unblocksignals(void);