diff --git a/std/jule/sema/func.jule b/std/jule/sema/func.jule
index 79cb20aeb..dfd8d85fb 100644
--- a/std/jule/sema/func.jule
+++ b/std/jule/sema/func.jule
@@ -266,12 +266,13 @@ impl FuncIns {
 				if !p2.Decl.IsSelf() {
 					ret false
 				}
-
 				if p1.Decl.IsRef() != p2.Decl.IsRef() {
 					ret false
 				}
-
-				ret true
+				if responsive {
+					ret p1.Decl.Mutable || !p2.Decl.Mutable
+				}
+				ret p1.Decl.Mutable == p2.Decl.Mutable
 			}
 
 			if responsive {
@@ -319,7 +320,7 @@ impl FuncIns {
 		if self.Decl.Ident != other.Decl.Ident {
 			ret false
 		}
-		if !self.EqualFunc(other, false) {
+		if !self.EqualFunc(other, true) {
 			ret false
 		}
 		if len(self.Decl.Generics) != len(other.Decl.Generics) {