diff --git a/headers/posix/arch/x86/signal.h b/headers/posix/arch/x86/signal.h
index 80a21590ef..a8146a9938 100644
--- a/headers/posix/arch/x86/signal.h
+++ b/headers/posix/arch/x86/signal.h
@@ -114,7 +114,7 @@ typedef struct new_extended_regs {
 	unsigned short	fp_ds;
 	unsigned short	_reserved_22_23;
 	unsigned long	mxcsr;
-	unsigned long	_reserved_28_31;
+	unsigned long	mxcsr_mask;
 	union {
 		fp_stack fp;
 		mmx_regs mmx;
diff --git a/headers/posix/arch/x86_64/signal.h b/headers/posix/arch/x86_64/signal.h
index c080a04adc..833db79dca 100644
--- a/headers/posix/arch/x86_64/signal.h
+++ b/headers/posix/arch/x86_64/signal.h
@@ -31,7 +31,7 @@ struct fpu_state {
 	unsigned long		rip;
 	unsigned long		rdp;
 	unsigned int		mxcsr;
-	unsigned int		mscsr_mask;
+	unsigned int		mxcsr_mask;
 
 	union {
 		struct x86_64_fp_register fp[8];