diff --git a/gba_memory.c b/gba_memory.c
index a09d008..ad2025e 100644
--- a/gba_memory.c
+++ b/gba_memory.c
@@ -1910,14 +1910,14 @@ void function_cc write_rtc(u32 address, u32 value)
       break;                                                                  \
   }                                                                           \
 
-u8 function_cc read_memory8(u32 address)
+u32 function_cc read_memory8(u32 address)
 {
   u8 value;
   read_memory(8);
   return value;
 }
 
-u32 read_memory8s(u32 address) {
+u32 function_cc read_memory8s(u32 address) {
   return (u32)((s8)read_memory8(address));
 }
 
@@ -1933,7 +1933,7 @@ u16 function_cc read_memory16_signed(u32 address)
   return value;
 }
 
-u32 read_memory16s(u32 address) {
+u32 function_cc read_memory16s(u32 address) {
   return (u32)((s16)read_memory16_signed(address));
 }
 
diff --git a/gba_memory.h b/gba_memory.h
index 3fc4435..6e26260 100644
--- a/gba_memory.h
+++ b/gba_memory.h
@@ -167,11 +167,11 @@ typedef enum
 #define FLASH_MANUFACTURER_PANASONIC 0x32
 #define FLASH_MANUFACTURER_SST       0xBF
 
-u8 function_cc read_memory8(u32 address);
-u32 read_memory8s(u32 address);
+u32 function_cc read_memory8(u32 address);
+u32 function_cc read_memory8s(u32 address);
 u32 function_cc read_memory16(u32 address);
 u16 function_cc read_memory16_signed(u32 address);
-u32 read_memory16s(u32 address);
+u32 function_cc read_memory16s(u32 address);
 u32 function_cc read_memory32(u32 address);
 cpu_alert_type function_cc write_memory8(u32 address, u8 value);
 cpu_alert_type function_cc write_memory16(u32 address, u16 value);