diff --git a/sdk/src/ed25519_instruction.rs b/sdk/src/ed25519_instruction.rs
index 45a8f1c2c2d932..a7bae6b4164a32 100644
--- a/sdk/src/ed25519_instruction.rs
+++ b/sdk/src/ed25519_instruction.rs
@@ -93,6 +93,7 @@ pub fn verify(
         return Err(PrecompileError::InvalidInstructionDataSize);
     }
     let num_signatures = data[0] as usize;
+    
     if num_signatures == 0 && data.len() > SIGNATURE_OFFSETS_START {
         return Err(PrecompileError::InvalidInstructionDataSize);
     }
diff --git a/sdk/src/secp256r1_instruction.rs b/sdk/src/secp256r1_instruction.rs
index 545cf52963759c..ca2e6a3e0313c6 100644
--- a/sdk/src/secp256r1_instruction.rs
+++ b/sdk/src/secp256r1_instruction.rs
@@ -142,7 +142,9 @@ pub fn verify(
         return Err(PrecompileError::InvalidInstructionDataSize);
     }
     let num_signatures = data[0] as usize;
-
+    if num_signatures == 0 {
+        return Err(PrecompileError::InvalidInstructionDataSize);
+    }
     if num_signatures > 8 {
         return Err(PrecompileError::InvalidInstructionDataSize);
     }