diff --git a/vm/os-linux-x86.32.hpp b/vm/os-linux-x86.32.hpp
index 1db87f995d..8fa7eff842 100644
--- a/vm/os-linux-x86.32.hpp
+++ b/vm/os-linux-x86.32.hpp
@@ -3,6 +3,32 @@
 namespace factor
 {
 
+// glibc lies about the contents of the fpstate the kernel provides, hiding the FXSR
+// environment
+struct _fpstate {
+	/* Regular FPU environment */
+	unsigned long   cw;
+	unsigned long   sw;
+	unsigned long   tag;
+	unsigned long   ipoff;
+	unsigned long   cssel;
+	unsigned long   dataoff;
+	unsigned long   datasel;
+	struct _fpreg   _st[8];
+	unsigned short  status;
+	unsigned short  magic;          /* 0xffff = regular FPU data only */
+	
+	/* FXSR FPU environment */
+	unsigned long   _fxsr_env[6];   /* FXSR FPU env is ignored */
+	unsigned long   mxcsr;
+	unsigned long   reserved;
+	struct _fpxreg  _fxsr_st[8];    /* FXSR FPU reg data is ignored */
+	struct _xmmreg  _xmm[8];
+	unsigned long   padding[56];
+};
+
+#define X86_FXSR_MAGIC          0x0000
+
 inline static void *ucontext_stack_pointer(void *uap)
 {
 	ucontext_t *ucontext = (ucontext_t *)uap;
@@ -11,15 +37,21 @@ inline static void *ucontext_stack_pointer(void *uap)
 
 inline static unsigned int uap_fpu_status(void *uap)
 {
-	// XXX mxcsr not available in i386 ucontext
 	ucontext_t *ucontext = (ucontext_t *)uap;
-	return ucontext->uc_mcontext.fpregs->sw;
+	struct _fpstate *fpregs = (struct _fpstate *)uap->uc_mcontext.fpregs;
+	if (fpregs->magic == X86_FXSR_MAGIC)
+	    return fpregs->sw | fpregs->mxcsr;
+	else
+	    return fpregs->sw;
 }
 
 inline static void uap_clear_fpu_status(void *uap)
 {
 	ucontext_t *ucontext = (ucontext_t *)uap;
-	ucontext->uc_mcontext.fpregs->sw = 0;
+	struct _fpstate *fpregs = (struct _fpstate *)uap->uc_mcontext.fpregs;
+	fpregs->sw = 0;
+	if (fpregs->magic == X86_FXSR_MAGIC)
+	    fpregs->mxcsr &= 0xffffffc0;
 }
 
 #define UAP_PROGRAM_COUNTER(ucontext) \