diff --git a/src/decoder/image.rs b/src/decoder/image.rs
index c678da8..c525ed2 100644
--- a/src/decoder/image.rs
+++ b/src/decoder/image.rs
@@ -486,11 +486,11 @@ impl Image {
         } else if padding.0 > 0 && self.predictor == Predictor::FloatingPoint {
             // The floating point predictor shuffles the padding bytes into the encoded output, so
             // this case is handled specially when needed.
+            let mut encoded = vec![0u8; chunk_dimensions.0 * samples * byte_len];
             for row in 0..(chunk_dimensions.1 - padding.1) {
                 let row_start = row * output_width * samples;
                 let row_end = row_start + (chunk_dimensions.0 - padding.0) * samples;
 
-                let mut encoded = vec![0u8; chunk_dimensions.0 * samples * byte_len];
                 reader.read_exact(&mut encoded)?;
                 match buffer.subrange(row_start..row_end) {
                     DecodingBuffer::F32(buf) => fp_predict_f32(&mut encoded, buf, samples),
diff --git a/src/decoder/mod.rs b/src/decoder/mod.rs
index 22face5..c4299af 100644
--- a/src/decoder/mod.rs
+++ b/src/decoder/mod.rs
@@ -416,7 +416,9 @@ fn fix_endianness_and_predict(
                 DecodingBuffer::I16(buf) => rev_hpredict_nsamp(buf, samples),
                 DecodingBuffer::I32(buf) => rev_hpredict_nsamp(buf, samples),
                 DecodingBuffer::I64(buf) => rev_hpredict_nsamp(buf, samples),
-                DecodingBuffer::F32(_) | DecodingBuffer::F64(_) => unreachable!(),
+                DecodingBuffer::F32(_) | DecodingBuffer::F64(_) => {
+                    unreachable!("Caller should have validated arguments. Please file a bug.")
+                }
             }
         }
         Predictor::FloatingPoint => {
@@ -424,7 +426,7 @@ fn fix_endianness_and_predict(
             match image {
                 DecodingBuffer::F32(buf) => fp_predict_f32(&mut buffer_copy, buf, samples),
                 DecodingBuffer::F64(buf) => fp_predict_f64(&mut buffer_copy, buf, samples),
-                _ => unreachable!(),
+                _ => unreachable!("Caller should have validated arguments. Please file a bug."),
             }
         }
         Predictor::__NonExhaustive => unreachable!(),