diff --git a/document/core/text/values.rst b/document/core/text/values.rst
index 918d35ab4e..1f4c1bbfdb 100644
--- a/document/core/text/values.rst
+++ b/document/core/text/values.rst
@@ -88,28 +88,26 @@ Floating-Point
 .. math::
    \begin{array}{llclll@{\qquad\qquad}l}
    \production{decimal floating-point fraction} & \Tfrac &::=&
-     \epsilon &\Rightarrow& 0 \\ &&|&
-     d{:}\Tdigit~~q{:}\Tfrac &\Rightarrow& (d+q)/10 \\ &&|&
-     d{:}\Tdigit~~\text{\_}~~p{:}\Tdigit~~q{:}\Tfrac &\Rightarrow& (d+(p+q)/10)/10 \\
+     d{:}\Tdigit &\Rightarrow& d/10 \\ &&|&
+     d{:}\Tdigit~~\text{\_}^?~~p{:}\Tfrac &\Rightarrow& (d+p/10)/10 \\
    \production{hexadecimal floating-point fraction} & \Thexfrac &::=&
-     \epsilon &\Rightarrow& 0 \\ &&|&
-     h{:}\Thexdigit~~q{:}\Thexfrac &\Rightarrow& (h+q)/16 \\ &&|&
-     h{:}\Thexdigit~~\text{\_}~~~~p{:}\Thexdigit~~q{:}\Thexfrac &\Rightarrow& (h+(p+q)/16)/16 \\
+     h{:}\Thexdigit &\Rightarrow& h/16 \\ &&|&
+     h{:}\Thexdigit~~\text{\_}^?~~p{:}\Thexfrac &\Rightarrow& (h+p/16)/16 \\
    \production{decimal floating-point number} & \Tfloat &::=&
-     p{:}\Tnum
+     p{:}\Tnum~\text{.}^?
        &\Rightarrow& p \\ &&|&
      p{:}\Tnum~\text{.}~q{:}\Tfrac
        &\Rightarrow& p+q \\ &&|&
-     p{:}\Tnum~(\text{E}~|~\text{e})~{\pm}{:}\Tsign~e{:}\Tnum
+     p{:}\Tnum~\text{.}^?~(\text{E}~|~\text{e})~{\pm}{:}\Tsign~e{:}\Tnum
        &\Rightarrow& p\cdot 10^{\pm e} \\ &&|&
      p{:}\Tnum~\text{.}~q{:}\Tfrac~(\text{E}~|~\text{e})~{\pm}{:}\Tsign~e{:}\Tnum
        &\Rightarrow& (p+q)\cdot 10^{\pm e} \\
    \production{hexadecimal floating-point number} & \Thexfloat &::=&
-     \text{0x}~p{:}\Thexnum
+     \text{0x}~p{:}\Thexnum~\text{.}^?
        &\Rightarrow& p \\ &&|&
      \text{0x}~p{:}\Thexnum~\text{.}~q{:}\Thexfrac
        &\Rightarrow& p+q \\ &&|&
-     \text{0x}~p{:}\Thexnum~(\text{P}~|~\text{p})~{\pm}{:}\Tsign~e{:}\Tnum
+     \text{0x}~p{:}\Thexnum~\text{.}^?~(\text{P}~|~\text{p})~{\pm}{:}\Tsign~e{:}\Tnum
        &\Rightarrow& p\cdot 2^{\pm e} \\ &&|&
      \text{0x}~p{:}\Thexnum~\text{.}~q{:}\Thexfrac~(\text{P}~|~\text{p})~{\pm}{:}\Tsign~e{:}\Tnum
        &\Rightarrow& (p+q)\cdot 2^{\pm e}
diff --git a/test/core/const.wast b/test/core/const.wast
index 6e8931a063..5656502987 100644
--- a/test/core/const.wast
+++ b/test/core/const.wast
@@ -154,6 +154,13 @@
 (module (func (f64.const 0123456789.0123456789e019) drop))
 (module (func (f64.const 0123456789.0123456789e+019) drop))
 (module (func (f64.const 0123456789.0123456789e-019) drop))
+(module (func (f64.const 0_1_2_3_4_5_6_7_8_9) drop))
+(module (func (f64.const 0_1_2_3_4_5_6_7_8_9.) drop))
+(module (func (f64.const 0_1_2_3_4_5_6_7_8_9.0_1_2_3_4_5_6_7_8_9) drop))
+(module (func (f64.const 0_1_2_3_4_5_6_7_8_9e+0_1_9) drop))
+(module (func (f64.const 0_1_2_3_4_5_6_7_8_9.e+0_1_9) drop))
+(module (func (f64.const 0_1_2_3_4_5_6_7_8_9.0_1_2_3_4_5_6_7_8_9e0_1_9) drop))
+
 (module (func (f64.const 0x0123456789ABCDEFabcdef) drop))
 (module (func (f64.const 0x0123456789ABCDEFabcdefp019) drop))
 (module (func (f64.const 0x0123456789ABCDEFabcdefp+019) drop))
@@ -166,6 +173,14 @@
 (module (func (f64.const 0x0123456789ABCDEFabcdef.0123456789ABCDEFabcdefp019) drop))
 (module (func (f64.const 0x0123456789ABCDEFabcdef.0123456789ABCDEFabcdefp+019) drop))
 (module (func (f64.const 0x0123456789ABCDEFabcdef.0123456789ABCDEFabcdefp-019) drop))
+(module (func (f64.const 0x0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_a_b_c_d_e_f) drop))
+(module (func (f64.const 0x0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_a_b_c_d_e_f.) drop))
+(module (func (f64.const 0x0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_a_b_c_d_e_f.0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_a_b_c_d_e_f) drop))
+(module (func (f64.const 0x0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_a_b_c_d_e_fp0_1_9) drop))
+(module (func (f64.const 0x0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_a_b_c_d_e_f.p0_1_9) drop))
+(module (func (f64.const 0x0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_a_b_c_d_e_f.0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_a_b_c_d_e_fp0_1_9) drop))
+
+
 (assert_malformed
   (module quote "(func (f64.const) drop)")
   "unexpected token"