diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index 34e39adc0f..3222676ae5 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -210,23 +210,25 @@ bool static CheckPubKeyEncoding(const valtype &vchSig, unsigned int flags, Scrip
 }
 
 bool static CheckMinimalPush(const valtype& data, opcodetype opcode) {
+    // Excludes OP_1NEGATE, OP_1-16 since they are by definition minimal
+    assert(0 <= opcode && opcode <= OP_PUSHDATA4);
     if (data.size() == 0) {
-        // Could have used OP_0.
+        // Should have used OP_0.
         return opcode == OP_0;
     } else if (data.size() == 1 && data[0] >= 1 && data[0] <= 16) {
-        // Could have used OP_1 .. OP_16.
-        return opcode == OP_1 + (data[0] - 1);
+        // Should have used OP_1 .. OP_16.
+        return false;
     } else if (data.size() == 1 && data[0] == 0x81) {
-        // Could have used OP_1NEGATE.
-        return opcode == OP_1NEGATE;
+        // Should have used OP_1NEGATE.
+        return false;
     } else if (data.size() <= 75) {
-        // Could have used a direct push (opcode indicating number of bytes pushed + those bytes).
+        // Must have used a direct push (opcode indicating number of bytes pushed + those bytes).
         return opcode == data.size();
     } else if (data.size() <= 255) {
-        // Could have used OP_PUSHDATA.
+        // Must have used OP_PUSHDATA.
         return opcode == OP_PUSHDATA1;
     } else if (data.size() <= 65535) {
-        // Could have used OP_PUSHDATA2.
+        // Must have used OP_PUSHDATA2.
         return opcode == OP_PUSHDATA2;
     }
     return true;