diff --git a/FlowCrypt/Controllers/Compose/Extensions/ComposeViewController+Nodes.swift b/FlowCrypt/Controllers/Compose/Extensions/ComposeViewController+Nodes.swift
index 708d1ca21..5c5343b74 100644
--- a/FlowCrypt/Controllers/Compose/Extensions/ComposeViewController+Nodes.swift
+++ b/FlowCrypt/Controllers/Compose/Extensions/ComposeViewController+Nodes.swift
@@ -160,8 +160,22 @@ extension ComposeViewController {
             mutableString.append(styledQuote)
         }
 
-        if let signature = getSignature(), !mutableString.string.replacingOccurrences(of: "\r", with: "").contains(signature) {
-            mutableString.append(signature.attributed(.regular(17)))
+        if let signatureRaw = getSignature() {
+            func normalize(_ s: String) -> String {
+                return s
+                    .replacingOccurrences(of: "\r\n", with: "\n")
+                    .replacingOccurrences(of: "\r", with: "\n")
+                    // fix html signature duplicate issue
+                    // https://github.com/FlowCrypt/flowcrypt-ios/pull/2684#discussion_r2318361291
+                    .replacingOccurrences(of: "\u{00A0}", with: " ")
+                    .trimmingCharacters(in: .whitespacesAndNewlines)
+            }
+            let body = normalize(mutableString.string)
+            let signature = normalize(signatureRaw)
+            let alreadyHasSig = body.contains(signature)
+            if !alreadyHasSig {
+                mutableString.append(signatureRaw.attributed(.regular(17)))
+            }
         }
 
         let height = max(decorator.frame(for: mutableString).height, 40)