diff --git a/firmware/export/system.h b/firmware/export/system.h
index edbfee31e1..fc0b7506bc 100644
--- a/firmware/export/system.h
+++ b/firmware/export/system.h
@@ -93,7 +93,7 @@ static inline int set_irq_level(int level)
     return i;
 }
 
-static inline short SWAB16(short value)
+static inline unsigned short SWAB16(unsigned short value)
   /*
     result[15..8] = value[ 7..0];
     result[ 7..0] = value[15..8];
@@ -104,7 +104,7 @@ static inline short SWAB16(short value)
     return result;
 }
 
-static inline long SWAW32(long value)
+static inline unsigned long SWAW32(unsigned long value)
   /*
     result[31..16] = value[15.. 0];
     result[15.. 0] = value[31..16];
@@ -115,7 +115,7 @@ static inline long SWAW32(long value)
     return result;
 }
 
-static inline long SWAB32(long value)
+static inline unsigned long SWAB32(unsigned long value)
   /*
     result[31..24] = value[ 7.. 0];
     result[23..16] = value[15.. 8];