diff --git a/drv/rcc.c b/drv/rcc.c
index f755b0a..e36fe45 100644
--- a/drv/rcc.c
+++ b/drv/rcc.c
@@ -163,7 +163,7 @@ static void apply_speed_preset(void)
 
 	//try enabling HSE, fallback to HSI if HSE fails
 	regs->CR.HSEON = 1;
-	for (uint32_t i=0; i<1000; ++i) {
+	for (uint32_t i=0; i<10000; ++i) {
 		__asm__("nop");
 	}
 	if (regs->CR.HSERDY == 0x1) {
@@ -175,7 +175,7 @@ static void apply_speed_preset(void)
 	//configure PLL, fallback to HSI if PLL fails
 	regs->CFGR.PLLMUL = 0x7; //PLL x9
 	regs->CR.PLLON = 1;
-	for (uint32_t i=0; i<1000; ++i) {
+	for (uint32_t i=0; i<10000; ++i) {
 		__asm__("nop");
 	}
 	if (regs->CR.PLLRDY != 0x1) {