diff --git a/src/script/ismine.cpp b/src/script/ismine.cpp
--- a/src/script/ismine.cpp
+++ b/src/script/ismine.cpp
@@ -13,14 +13,15 @@
 
 typedef std::vector<uint8_t> valtype;
 
-unsigned int HaveKeys(const std::vector<valtype> &pubkeys,
-                      const CKeyStore &keystore) {
-    unsigned int nResult = 0;
+static bool HaveKeys(const std::vector<valtype> &pubkeys,
+                     const CKeyStore &keystore) {
     for (const valtype &pubkey : pubkeys) {
         CKeyID keyID = CPubKey(pubkey).GetID();
-        if (keystore.HaveKey(keyID)) ++nResult;
+        if (!keystore.HaveKey(keyID)) {
+            return false;
+        }
     }
-    return nResult;
+    return true;
 }
 
 isminetype IsMine(const CKeyStore &keystore, const CScript &scriptPubKey) {
@@ -84,8 +85,9 @@
             std::vector<valtype> keys(vSolutions.begin() + 1,
                                       vSolutions.begin() + vSolutions.size() -
                                           1);
-            if (HaveKeys(keys, keystore) == keys.size())
+            if (HaveKeys(keys, keystore)) {
                 return ISMINE_SPENDABLE;
+            }
             break;
         }
     }