diff --git a/arch/arm/src/str71x/str71x_internal.h b/arch/arm/src/str71x/str71x_internal.h
index 10a821506ed..5dea598de17 100644
--- a/arch/arm/src/str71x/str71x_internal.h
+++ b/arch/arm/src/str71x/str71x_internal.h
@@ -69,7 +69,7 @@
 
 #define STR71X_PLL1OUT ((STR71X_PLL1OUT_MUL * STR71X_CLK2) / STR71X_PLL1OUT_DIV)
 
-/* PLL2 OUTderives from HCLK */
+/* PLL2 OUT derives from HCLK */
 
 #define STR71X_PLL2OUT ((STR71X_PLL2OUT_MUL * STR71X_HCLK) / STR71X_PLL2OUT_DIV)