diff --git a/src/julia-parser.scm b/src/julia-parser.scm
index 83e1550b28e595..5adb2a9040a8d2 100644
--- a/src/julia-parser.scm
+++ b/src/julia-parser.scm
@@ -1154,20 +1154,20 @@
         (parse-atom s))))
 
 (define (parse-def s is-func anon)
-  (let ((ex  (parse-unary-prefix s)))
-    (if (and (pair? ex) (eq? (car ex) 'macrocall))
-      ex
-      (let* ((sig (if (or (and is-func (reserved-word? ex)) (initial-reserved-word? ex))
-                      (error (string "invalid name \"" ex "\""))
-                      (parse-call-chain s ex #f)))
-            (decl-sig
-              (if (and is-func (eq? (peek-token s) '|::|))
-                  (begin (take-token s)
-                        `(|::| ,sig ,(parse-call s)))
-                  sig)))
-        (if (eq? (peek-token s) 'where)
-            (parse-where-chain s decl-sig)
-            decl-sig)))))
+  (let* ((ex  (parse-unary-prefix s))
+         (sig
+            (if (and (pair? ex) (eq? (car ex) 'macrocall)) ex
+              (if (or (and is-func (reserved-word? ex)) (initial-reserved-word? ex))
+                    (error (string "invalid name \"" ex "\""))
+                    (parse-call-chain s ex #f))))
+          (decl-sig
+            (if (and is-func (eq? (peek-token s) '|::|))
+                (begin (take-token s)
+                      `(|::| ,sig ,(parse-call s)))
+                sig)))
+    (if (eq? (peek-token s) 'where)
+        (parse-where-chain s decl-sig)
+        decl-sig)))
 
 (define (disallowed-space-error lno ex t)
   (error (string "space before \"" t "\" not allowed in \""
@@ -1331,14 +1331,12 @@
 
 (define (valid-func-sig? paren sig)
   (and (pair? sig)
-       (or (eq? (car sig) 'macrocall)
-           (eq? (car sig) 'call)
-           (eq? (car sig) 'tuple)
+       (or (memq (car sig) '(macrocall call tuple))
            (and paren (eq? (car sig) 'block))
            (and paren (eq? (car sig) '...))
            (and (eq? (car sig) '|::|)
                 (pair? (cadr sig))
-                (eq? (car (cadr sig)) 'call))
+                (memq (car (cadr sig)) '(call macrocall)))
            (and (eq? (car sig) 'where)
                 (valid-func-sig? paren (cadr sig))))))
 
diff --git a/test/syntax.jl b/test/syntax.jl
index 2553056fc00b9a..21052f2e6292da 100644
--- a/test/syntax.jl
+++ b/test/syntax.jl
@@ -3865,3 +3865,25 @@ module UndefGlobal54954
 end
 using .UndefGlobal54954: theglobal54954
 @test Core.get_binding_type(@__MODULE__, :theglobal54954) === Int
+
+# PR# 55040 - Macrocall as function sig
+function callme end
+macro callmemacro(args...)
+    Expr(:call, esc(:callme), map(esc, args)...)
+end
+
+function @callmemacro(a::Int)
+    return 1
+end
+@callmemacro(b::Float64) = 2
+function @callmemacro(a::T, b::T) where T <: Int64
+    return 3
+end
+function @callmemacro(a::Int, b::Int, c::Int)::Float64
+    return 4
+end
+
+@test callme(1) === 1
+@test callme(2.0) === 2
+@test callme(3, 3) === 3
+@test callme(4, 4, 4) === 4.0