diff --git a/calyx-frontend/src/parser.rs b/calyx-frontend/src/parser.rs
index ac4541f334..2a48c2540e 100644
--- a/calyx-frontend/src/parser.rs
+++ b/calyx-frontend/src/parser.rs
@@ -302,6 +302,22 @@ impl CalyxParser {
         Ok(float_val)
     }
 
+    fn ieee754_const(input: Node) -> ParseResult<BitNum> {
+        println!("parsing iee754");
+        let span = Self::get_span(&input);
+        let val = match_nodes!(
+            input.clone().into_children();
+            [float(val)] => val
+        );
+        let bit_pattern = val.to_bits();
+        Ok(BitNum {
+            width: 64,
+            num_type: NumType::Hex,
+            val: bit_pattern,
+            span,
+        })
+    }
+
     fn num_lit(input: Node) -> ParseResult<BitNum> {
         let span = Self::get_span(&input);
         let num = match_nodes!(
@@ -330,21 +346,7 @@ impl CalyxParser {
                     val,
                     span
                 },
-            [bitwidth(width), float(val)] => {
-                let bit_pattern = if width == 32 {
-                    (val as f32).to_bits() as u64
-                } else if width == 64 {
-                    val.to_bits()
-                } else {
-                    return Err(input.error("Unsupported bitwidth for floating-point number"));
-                };
-                BitNum {
-                    width,
-                    num_type: NumType::Hex,
-                    val: bit_pattern,
-                    span
-                }
-            },
+            [ieee754_const(val)] => val,
 
         );
 
diff --git a/calyx-frontend/src/syntax.pest b/calyx-frontend/src/syntax.pest
index d01f1a136c..6dc5b80f93 100644
--- a/calyx-frontend/src/syntax.pest
+++ b/calyx-frontend/src/syntax.pest
@@ -18,17 +18,20 @@ octal =   @{ ASCII_HEX_DIGIT+ }
 hex =     @{ ASCII_HEX_DIGIT+ }
 float =   @{ ASCII_DIGIT+ ~ "." ~ ASCII_DIGIT+ }
 
+ieee754_const = { "ieee754_const(" ~ float ~ ")" }
+
 // `$` creates a compound rule which ignores whitespace while allowing for
 // inner rules (`@` makes inner rules silent).
 // See: https://pest.rs/book/print.html#atomic
 num_lit = ${
-      bitwidth
+      (bitwidth
       ~ "'"
       ~ ( "d" ~ decimal
         | "b" ~ binary
         | "x" ~ hex
-        | "o" ~ octal
-        | "f" ~ float)
+        | "o" ~ octal)
+      )
+      | ieee754_const
 }
 
 char = { !"\"" ~ ANY }
diff --git a/tests/correctness/float/float-const.futil b/tests/correctness/float/float-const.futil
index 4bbfc8cdd8..969494e51c 100644
--- a/tests/correctness/float/float-const.futil
+++ b/tests/correctness/float/float-const.futil
@@ -10,7 +10,7 @@ component main<"toplevel"=1,>(@clk clk: 1, @reset reset: 1, @go go: 1) -> (@done
   wires {
     group read {
         mem_read.addr0 = 1'b0;
-        reg0.in = mem_read.read_data;
+        reg0.in = ieee754_const(1.00);
         reg0.write_en = 1'b1;
         read[done] = reg0.done;
     }