diff --git a/src/script/sign.h b/src/script/sign.h
index 2fc4575e5..5b45777a2 100644
--- a/src/script/sign.h
+++ b/src/script/sign.h
@@ -300,6 +300,7 @@ struct PSBTInput
     template <typename Stream>
     inline void Unserialize(Stream& s) {
         // Read loop
+        bool found_sep = false;
         while(!s.empty()) {
             // Read
             std::vector<unsigned char> key;
@@ -307,7 +308,10 @@ struct PSBTInput
 
             // the key is empty if that was actually a separator byte
             // This is a special case for key lengths 0 as those are not allowed (except for separator)
-            if (key.empty()) return;
+            if (key.empty()) {
+                found_sep = true;
+                break;
+            }
 
             // First byte of key is the type
             unsigned char type = key[0];
@@ -422,6 +426,10 @@ struct PSBTInput
                     break;
             }
         }
+
+        if (!found_sep) {
+            throw std::ios_base::failure("Separator is missing at the end of an input map");
+        }
     }
 
     template <typename Stream>
@@ -475,6 +483,7 @@ struct PSBTOutput
     template <typename Stream>
     inline void Unserialize(Stream& s) {
         // Read loop
+        bool found_sep = false;
         while(!s.empty()) {
             // Read
             std::vector<unsigned char> key;
@@ -482,7 +491,10 @@ struct PSBTOutput
 
             // the key is empty if that was actually a separator byte
             // This is a special case for key lengths 0 as those are not allowed (except for separator)
-            if (key.empty()) return;
+            if (key.empty()) {
+                found_sep = true;
+                break;
+            }
 
             // First byte of key is the type
             unsigned char type = key[0];
@@ -527,6 +539,10 @@ struct PSBTOutput
                 }
             }
         }
+
+        if (!found_sep) {
+            throw std::ios_base::failure("Separator is missing at the end of an output map");
+        }
     }
 
     template <typename Stream>
@@ -602,6 +618,7 @@ struct PartiallySignedTransaction
         }
 
         // Read global data
+        bool found_sep = false;
         while(!s.empty()) {
             // Read
             std::vector<unsigned char> key;
@@ -609,7 +626,10 @@ struct PartiallySignedTransaction
 
             // the key is empty if that was actually a separator byte
             // This is a special case for key lengths 0 as those are not allowed (except for separator)
-            if (key.empty()) break;
+            if (key.empty()) {
+                found_sep = true;
+                break;
+            }
 
             // First byte of key is the type
             unsigned char type = key[0];
@@ -649,6 +669,10 @@ struct PartiallySignedTransaction
             }
         }
 
+        if (!found_sep) {
+            throw std::ios_base::failure("Separator is missing at the end of the global map");
+        }
+
         // Make sure that we got an unsigned tx
         if (!tx) {
             throw std::ios_base::failure("No unsigned transcation was provided");
diff --git a/test/functional/data/rpc_psbt.json b/test/functional/data/rpc_psbt.json
index dd40a096d..57f2608ee 100644
--- a/test/functional/data/rpc_psbt.json
+++ b/test/functional/data/rpc_psbt.json
@@ -17,7 +17,8 @@
         "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",
         "cHNidP8BAHMCAAAAATAa6YblFqHsisW0vGVz0y+DtGXiOtdhZ9aLOOcwtNvbAAAAAAD/////AnR7AQAAAAAAF6kUA6oXrogrXQ1Usl1jEE5P/s57nqKHYEOZOwAAAAAXqRS5IbG6b3IuS/qDtlV6MTmYakLsg4cAAAAAAAEBHwDKmjsAAAAAFgAU0tlLZK4IWH7vyO6xh8YB6Tn5A3wCAwABAAAAAAEAFgAUYunpgv/zTdgjlhAxawkM0qO3R8sAAQAiACCHa62DLx0WgBXtQSMqnqZaGBXZ7xPA74dZ9ktbKyeKZQEBJVEhA7fOI6AcW0vwCmQlN836uzFbZoMyhnR471EwnSvVf4qHUa4A",
         "cHNidP8BAHMCAAAAATAa6YblFqHsisW0vGVz0y+DtGXiOtdhZ9aLOOcwtNvbAAAAAAD/////AnR7AQAAAAAAF6kUA6oXrogrXQ1Usl1jEE5P/s57nqKHYEOZOwAAAAAXqRS5IbG6b3IuS/qDtlV6MTmYakLsg4cAAAAAAAEBHwDKmjsAAAAAFgAU0tlLZK4IWH7vyO6xh8YB6Tn5A3wAAgAAFgAUYunpgv/zTdgjlhAxawkM0qO3R8sAAQAiACCHa62DLx0WgBXtQSMqnqZaGBXZ7xPA74dZ9ktbKyeKZQEBJVEhA7fOI6AcW0vwCmQlN836uzFbZoMyhnR471EwnSvVf4qHUa4A",
-        "cHNidP8BAHMCAAAAATAa6YblFqHsisW0vGVz0y+DtGXiOtdhZ9aLOOcwtNvbAAAAAAD/////AnR7AQAAAAAAF6kUA6oXrogrXQ1Usl1jEE5P/s57nqKHYEOZOwAAAAAXqRS5IbG6b3IuS/qDtlV6MTmYakLsg4cAAAAAAAEBHwDKmjsAAAAAFgAU0tlLZK4IWH7vyO6xh8YB6Tn5A3wAAQAWABRi6emC//NN2COWEDFrCQzSo7dHywABACIAIIdrrYMvHRaAFe1BIyqeploYFdnvE8Dvh1n2S1srJ4plIQEAJVEhA7fOI6AcW0vwCmQlN836uzFbZoMyhnR471EwnSvVf4qHUa4A"
+        "cHNidP8BAHMCAAAAATAa6YblFqHsisW0vGVz0y+DtGXiOtdhZ9aLOOcwtNvbAAAAAAD/////AnR7AQAAAAAAF6kUA6oXrogrXQ1Usl1jEE5P/s57nqKHYEOZOwAAAAAXqRS5IbG6b3IuS/qDtlV6MTmYakLsg4cAAAAAAAEBHwDKmjsAAAAAFgAU0tlLZK4IWH7vyO6xh8YB6Tn5A3wAAQAWABRi6emC//NN2COWEDFrCQzSo7dHywABACIAIIdrrYMvHRaAFe1BIyqeploYFdnvE8Dvh1n2S1srJ4plIQEAJVEhA7fOI6AcW0vwCmQlN836uzFbZoMyhnR471EwnSvVf4qHUa4A",
+        "cHNidP8BAHMCAAAAAbiWoY6pOQepFsEGhUPXaulX9rvye2NH+NrdlAHg+WgpAQAAAAD/////AkBLTAAAAAAAF6kUqWwXCcLM5BN2zoNqMNT5qMlIi7+HQEtMAAAAAAAXqRSVF/in2XNxAlN1OSxkyp0z+Wtg2YcAAAAAAAEBIBNssgAAAAAAF6kUamsvautR8hRlMRY6OKNTx03DK96HAQcXFgAUo8u1LWpHprjt/uENAwBpGZD0UH0BCGsCRzBEAiAONfH3DYiw67ZbylrsxCF/XXpVwyWBRgofyRbPslzvwgIgIKCsWw5sHSIPh1icNvcVLZLHWj6NA7Dk+4Os2pOnMbQBIQPGStfYHPtyhpV7zIWtn0Q4GXv5gK1zy/tnJ+cBXu4iiwABABYAFMwmJQEz+HDpBEEabxJ5PogPsqZRAAEAFgAUyCrGc3h3FYCmiIspbv2pSTKZ5jU"
     ],
     "valid" : [
         "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",