diff --git a/include/libopencm3/stm32/g4/rcc.h b/include/libopencm3/stm32/g4/rcc.h
index 74cc10f2..c1d38a90 100644
--- a/include/libopencm3/stm32/g4/rcc.h
+++ b/include/libopencm3/stm32/g4/rcc.h
@@ -574,12 +574,12 @@
 
 #define RCC_CCIPR_ADC345SEL_NONE	0
 #define RCC_CCIPR_ADC345SEL_PLLP	1
-#define RCC_CCIPR_ADC345SEL_SYS		2
+#define RCC_CCIPR_ADC345SEL_SYSCLK		2
 #define RCC_CCIPR_ADC345SEL_SHIFT	30
 
 #define RCC_CCIPR_ADC12SEL_NONE		0
 #define RCC_CCIPR_ADC12SEL_PLLP		1
-#define RCC_CCIPR_ADC12SEL_SYS		2
+#define RCC_CCIPR_ADC12SEL_SYSCLK	2
 #define RCC_CCIPR_ADC12SEL_SHIFT	28
 
 #define RCC_CCIPR_CLK48SEL_HSI48	0
@@ -591,13 +591,13 @@
 #define RCC_CCIPR_FDCANSEL_PCLK		2
 #define RCC_CCIPR_FDCANSEL_SHIFT	24
 
-#define RCC_CCIPR_I2S23SEL_SYS		0
+#define RCC_CCIPR_I2S23SEL_SYSCLK	0
 #define RCC_CCIPR_I2S23SEL_PLLQ		1
 #define RCC_CCIPR_I2S23SEL_EXT		2
 #define RCC_CCIPR_I2S23SEL_SHI16	3
 #define RCC_CCIPR_I2S23SEL_SHIFT	22
 
-#define RCC_CCIPR_SAI1SEL_SYS		0
+#define RCC_CCIPR_SAI1SEL_SYSCLK	0
 #define RCC_CCIPR_SAI1SEL_PLLQ		1
 #define RCC_CCIPR_SAI1SEL_EXT		2
 #define RCC_CCIPR_SAI1SEL_HSI16		3
@@ -610,14 +610,14 @@
 #define RCC_CCIPR_LPTIM1SEL_SHIFT	18
 
 #define RCC_CCIPR_I2CxSEL_PCLK		0
-#define RCC_CCIPR_I2CxSEL_SYS		1
+#define RCC_CCIPR_I2CxSEL_SYSCLK	1
 #define RCC_CCIPR_I2CxSEL_HSI16		2
 #define RCC_CCIPR_I2C3SEL_SHIFT		16
 #define RCC_CCIPR_I2C2SEL_SHIFT		14
 #define RCC_CCIPR_I2C1SEL_SHIFT		12
 
 #define RCC_CCIPR_USARTxSEL_PCLK	0
-#define RCC_CCIPR_USARTxSEL_SYSCLK		1
+#define RCC_CCIPR_USARTxSEL_SYSCLK	1
 #define RCC_CCIPR_USARTxSEL_HSI16	2
 #define RCC_CCIPR_USARTxSEL_LSE		3