diff --git a/src/soundloader_opus.cpp b/src/soundloader_opus.cpp
index 79252641cf..9e1860f3be 100644
--- a/src/soundloader_opus.cpp
+++ b/src/soundloader_opus.cpp
@@ -9,6 +9,7 @@
 
 #include "stdafx.h"
 
+#include "debug.h"
 #include "misc/autorelease.hpp"
 #include "random_access_file_type.h"
 #include "sound_type.h"
@@ -54,7 +55,10 @@ public:
 
 		int error = 0;
 		auto of = AutoRelease<OggOpusFile, op_free>(op_open_memory(tmp.data(), tmp.size(), &error));
-		if (error != 0) return false;
+		if (error != 0) {
+			Debug(grf, 0, "SoundLoader_Opus: Unable to open stream.");
+			return false;
+		}
 
 		size_t datapos = 0;
 		for (;;) {
@@ -64,8 +68,15 @@ public:
 			int read = op_read(of.get(), reinterpret_cast<opus_int16 *>(&data[datapos]), DECODE_BUFFER_BYTES, &link_index);
 			if (read == 0) break;
 
-			if (read < 0 || op_channel_count(of.get(), link_index) != 1) {
-				/* Error reading, or incorrect channel count. */
+			if (read < 0) {
+				Debug(grf, 0, "SoundLoader_Opus: Unexpected end of stream.");
+				data.clear();
+				return false;
+			}
+
+			int channels = op_channel_count(of.get(), link_index);
+			if (channels != 1) {
+				Debug(grf, 0, "SoundLoader_Opus: Unsupported channels {}, expected 1.", channels);
 				data.clear();
 				return false;
 			}
diff --git a/src/soundloader_wav.cpp b/src/soundloader_wav.cpp
index 72dbf0a056..77db237034 100644
--- a/src/soundloader_wav.cpp
+++ b/src/soundloader_wav.cpp
@@ -8,8 +8,8 @@
 /** @file soundloader_wav.cpp Loading of wav sounds. */
 
 #include "stdafx.h"
-#include "core/bitmath_func.hpp"
 #include "core/math_func.hpp"
+#include "debug.h"
 #include "random_access_file_type.h"
 #include "sound_type.h"
 #include "soundloader_type.h"
@@ -39,10 +39,16 @@ public:
 
 			if (tag == std::byteswap<uint32_t>('fmt ')) {
 				uint16_t format = file.ReadWord();
-				if (format != 1) return false; // File must be uncompressed PCM
+				if (format != 1) {
+					Debug(grf, 0, "SoundLoader_Wav: Unsupported format {}, expected 1 (uncompressed PCM).", format);
+					return false;
+				}
 
 				sound.channels = file.ReadWord();
-				if (sound.channels != 1) return false; // File must be mono.
+				if (sound.channels != 1) {
+					Debug(grf, 0, "SoundLoader_Wav: Unsupported channels {}, expected 1.", sound.channels);
+					return false;
+				}
 
 				sound.rate = file.ReadDword();
 				if (!new_format) sound.rate = DEFAULT_SAMPLE_RATE; // All old samples should be played at 11025 Hz.
@@ -51,13 +57,20 @@ public:
 				file.ReadWord();  // alignment
 
 				sound.bits_per_sample = file.ReadWord();
-				if (sound.bits_per_sample != 8 && sound.bits_per_sample != 16) return false; // File must be 8 or 16 BPS.
+				if (sound.bits_per_sample != 8 && sound.bits_per_sample != 16) {
+					Debug(grf, 0, "SoundLoader_Wav: Unsupported bits_per_sample {}, expected 8 or 16.", sound.bits_per_sample);
+					return false;
+				}
 
 				/* We've read 16 bytes of this chunk, we can skip anything extra. */
 				size -= 16;
 			} else if (tag == std::byteswap<uint32_t>('data')) {
 				uint align = sound.channels * sound.bits_per_sample / 8;
-				if (Align(size, align) != size) return false; // Ensure length is aligned correctly for channels and BPS.
+				if (Align(size, align) != size) {
+					/* Ensure length is aligned correctly for channels and BPS. */
+					Debug(grf, 0, "SoundLoader_Wav: Unexpected end of stream.");
+					return false;
+				}
 
 				if (size == 0) return true; // No need to continue.