diff --git a/fco2/GenerateC.hs b/fco2/GenerateC.hs
index fa15306..d61dfaa 100644
--- a/fco2/GenerateC.hs
+++ b/fco2/GenerateC.hs
@@ -122,8 +122,7 @@ genName n = tell [[if c == '.' then '_' else c | c <- A.nameName n]]
 --{{{  types
 scalarType :: A.Type -> Maybe String
 scalarType A.Bool = Just "bool"
--- FIXME: This probably isn't right; we might have to explicitly cast string literals...
-scalarType A.Byte = Just "char"
+scalarType A.Byte = Just "uint8_t"
 scalarType A.Int = Just "int"
 scalarType A.Int16 = Just "int16_t"
 scalarType A.Int32 = Just "int32_t"
diff --git a/fco2/tock_support.h b/fco2/tock_support.h
index 719d8f5..71f9a24 100644
--- a/fco2/tock_support.h
+++ b/fco2/tock_support.h
@@ -17,8 +17,8 @@
 //{{{ mostneg/mostpos
 #define occam_mostneg_bool false
 #define occam_mostpos_bool true
-#define occam_mostneg_char CHAR_MIN
-#define occam_mostpos_char CHAR_MAX
+#define occam_mostneg_uint8_t 0
+#define occam_mostpos_uint8_t UINT8_MAX
 #define occam_mostneg_int INT_MIN
 #define occam_mostpos_int INT_MAX
 #define occam_mostneg_int16_t INT16_MIN
@@ -112,13 +112,13 @@ static int occam_check_index (int i, int limit, const char *pos) {
 		return a % b; \
 	}
 
-//{{{ char
-MAKE_RANGE_CHECK(char, "%d")
-MAKE_ADD(char)
-MAKE_SUBTR(char)
-MAKE_MUL(char)
-MAKE_DIV(char)
-MAKE_REM(char)
+//{{{ uint8_t
+MAKE_RANGE_CHECK(uint8_t, "%d")
+MAKE_ADD(uint8_t)
+MAKE_SUBTR(uint8_t)
+MAKE_MUL(uint8_t)
+MAKE_DIV(uint8_t)
+MAKE_REM(uint8_t)
 //}}}
 //{{{ int16_t
 MAKE_RANGE_CHECK(int16_t, "%d")