diff --git a/mendel.c b/mendel.c
index d83b641..600074a 100644
--- a/mendel.c
+++ b/mendel.c
@@ -16,14 +16,15 @@
 #include	"debug.h"
 #include	"sersendf.h"
 #include	"heater.h"
+#include	"analog.h"
 
 void io_init(void) {
 	// disable modules we don't use
 	#ifdef PRR
-		PRR = MASK(PRTWI) | MASK(PRADC);
+		PRR = MASK(PRTWI) | MASK(PRADC) | MASK(PRSPI);
 	#endif
 	#ifdef PRR0
-		PRR0 = MASK(PRTWI) | MASK(PRADC);
+		PRR0 = MASK(PRTWI) | MASK(PRADC) | MASK(PRSPI);
 		#ifdef PRR1
 			PRR1 = 0xFF;
 		#endif
@@ -97,6 +98,9 @@ void init(void) {
 	// set up default feedrate
 	current_position.F = startpoint.F = next_target.target.F = SEARCH_FEEDRATE_Z;
 
+	// start up analog read interrupt loop, if anything uses analog as determined by ANALOG_MASK in your machine.h
+	analog_init();
+	
 	// enable interrupts
 	sei();
 
diff --git a/temp.c b/temp.c
index 1e5f7d3..162879b 100644
--- a/temp.c
+++ b/temp.c
@@ -88,6 +88,12 @@ uint16_t temp_read() {
 	uint16_t temp;
 
 #ifdef	TEMP_MAX6675
+	#ifdef	PRR
+		PRR &= ~MASK(PRSPI);
+	#elif defined PRR0
+		PRR0 &= ~MASK(PRSPI);
+	#endif
+
 	SPCR = MASK(MSTR) | MASK(SPE) | MASK(SPR0);
 
 	// enable MAX6675