diff --git a/doc/guides/mrbconf.md b/doc/guides/mrbconf.md
index dbdac75ad..717b9c397 100644
--- a/doc/guides/mrbconf.md
+++ b/doc/guides/mrbconf.md
@@ -76,8 +76,8 @@ end
 
 `MRB_USE_FLOAT32`
 
-- When defined single precision floating-point type(C type `float`) is used as `mrb_float`.
-- Otherwise, double precision floating-point type(C type `double`) is used as `mrb_float`.
+- When defined single-precision floating-point type(C type `float`) is used as `mrb_float`.
+- Otherwise, double-precision floating-point type(C type `double`) is used as `mrb_float`.
 
 `MRB_NO_FLOAT`
 
diff --git a/doc/mruby3.0.md b/doc/mruby3.0.md
index cf9092aa3..c1acb5ece 100644
--- a/doc/mruby3.0.md
+++ b/doc/mruby3.0.md
@@ -60,7 +60,7 @@ Some configuration macro names are changed for consistency (use `MRB_USE_XXX`
 | `DISABLE_MIRB_UNDERSCORE`      | `MRB_NO_MIRB_UNDERSCORE`  |
 
 - `MRB_USE_FLOAT32` is changed from `MRB_USE_FLOAT` to make sure `float` here
-  means using single precision float, and not the opposite of `MRB_NO_FLOAT`.
+  means using single-precision float, and not the opposite of `MRB_NO_FLOAT`.
 - `MRB_USE_METHOD_T_STRUCT` uses `struct` version of `mrb_method_t`. More
   portable but consumes more memory. Turned on by default on 32bit platforms.
 - `MRB_` prefix is added to those without.