diff --git a/Source/astcenc.h b/Source/astcenc.h
index ffce903e1c5134a867ade6ae81a5adc81ecfc3bc..4d8836d88c6a2246665de138fe829e68310dc345 100644
--- a/Source/astcenc.h
+++ b/Source/astcenc.h
@@ -264,7 +264,10 @@ enum astcenc_error {
 	ASTCENC_ERR_DTRACE_FAILURE,
 #endif
 #if QUALITY_CONTROL
-	ASTCENC_ERR_BAD_QUALITY_CHECK
+	ASTCENC_ERR_BAD_QUALITY_CHECK,
+#endif
+#ifdef ASTC_CUSTOMIZED_ENABLE
+	ASTCENC_ERR_DLOPEN_FAILED
 #endif
 };
 
@@ -938,6 +941,7 @@ public:
 		if (!astcCustomizedSoOpened_ || astcCustomizedSoHandle_ == nullptr)
 		{
 			printf("astcenc customized so is not be opened when dlclose!\n");
+			return;
 		}
 #if defined(_WIN32) && !defined(__CYGWIN__)
 		if (!FreeLibrary(astcCustomizedSoHandle_))
diff --git a/Source/astcenc_block_sizes.cpp b/Source/astcenc_block_sizes.cpp
index 9e53ff28730f819a82072b2c1df3902abba315d9..e7b5348aa0b65c0731d0b20418af4adaa3490ca4 100644
--- a/Source/astcenc_block_sizes.cpp
+++ b/Source/astcenc_block_sizes.cpp
@@ -789,7 +789,11 @@ static void construct_dt_entry_2d(
  * @param      mode_cutoff      Percentile cutoff in range [0,1]. Low values more likely to be used.
  * @param[out] bsd              The block size descriptor to populate.
  */
+#ifdef ASTC_CUSTOMIZED_ENABLE
+static bool construct_block_size_descriptor_2d(
+#else
 static void construct_block_size_descriptor_2d(
+#endif
 	QualityProfile privateProfile,
 	unsigned int x_texels,
 	unsigned int y_texels,
@@ -858,15 +862,22 @@ static void construct_block_size_descriptor_2d(
 				continue;
 			}
 #ifdef ASTC_CUSTOMIZED_ENABLE
-			if (!g_astcCustomizedSoManager.LoadSutCustomizedSo() ||
-				g_astcCustomizedSoManager.isCustomizedBlockModeFunc_ == nullptr)
+			if (privateProfile == CUSTOMIZED_PROFILE)
 			{
-				printf("astcenc customized so dlopen failed or isCustomizedBlockModeFunc_ is nullptr!\n");
-				return;
-			}
-			if ((privateProfile == CUSTOMIZED_PROFILE) && (!g_astcCustomizedSoManager.isCustomizedBlockModeFunc_(i)))
-			{
-				continue;
+				if (!g_astcCustomizedSoManager.LoadSutCustomizedSo() ||
+					g_astcCustomizedSoManager.isCustomizedBlockModeFunc_ == nullptr)
+				{
+					printf("astcenc customized so dlopen failed or isCustomizedBlockModeFunc_ is nullptr!\n");
+					delete wb;
+#if !defined(ASTCENC_DECOMPRESS_ONLY)
+					delete[] percentiles;
+#endif
+					return false;
+				}
+				if (!g_astcCustomizedSoManager.isCustomizedBlockModeFunc_(i))
+				{
+					continue;
+				}
 			}
 #endif
 			// Decode parameters
@@ -997,6 +1008,9 @@ static void construct_block_size_descriptor_2d(
 	assign_kmeans_texels(bsd);
 
 	delete wb;
+#ifdef ASTC_CUSTOMIZED_ENABLE
+	return true;
+#endif
 }
 
 /**
@@ -1182,7 +1196,11 @@ static void construct_block_size_descriptor_3d(
 }
 
 /* See header for documentation. */
+#ifdef ASTC_CUSTOMIZED_ENABLE
+bool init_block_size_descriptor(
+#else
 void init_block_size_descriptor(
+#endif
 	QualityProfile privateProfile,
 	unsigned int x_texels,
 	unsigned int y_texels,
@@ -1198,8 +1216,18 @@ void init_block_size_descriptor(
 	}
 	else
 	{
+#ifdef ASTC_CUSTOMIZED_ENABLE
+		if (!construct_block_size_descriptor_2d(privateProfile, x_texels, y_texels, can_omit_modes, mode_cutoff, bsd))
+		{
+			return false;
+		}
+#else
 		construct_block_size_descriptor_2d(privateProfile, x_texels, y_texels, can_omit_modes, mode_cutoff, bsd);
+#endif
 	}
 
 	init_partition_tables(bsd, can_omit_modes, partition_count_cutoff);
+#ifdef ASTC_CUSTOMIZED_ENABLE
+	return true;
+#endif
 }
diff --git a/Source/astcenc_entry.cpp b/Source/astcenc_entry.cpp
index 212658873e0b8379e86b62c4524588dd1f363e65..5a1ad96a212224ce5f0ccba105ef38740cfc3aa3 100644
--- a/Source/astcenc_entry.cpp
+++ b/Source/astcenc_entry.cpp
@@ -706,11 +706,25 @@ astcenc_error astcenc_context_alloc(
 	}
 
 	bool can_omit_modes = static_cast<bool>(config.flags & ASTCENC_FLG_SELF_DECOMPRESS_ONLY);
+#ifdef ASTC_CUSTOMIZED_ENABLE
+	if (!init_block_size_descriptor(ctx->config.privateProfile, config.block_x, config.block_y, config.block_z,
+	                           can_omit_modes,
+	                           config.tune_partition_count_limit,
+	                           static_cast<float>(config.tune_block_mode_limit) / 100.0f,
+	                           *ctx->bsd))
+	{
+		aligned_free<block_size_descriptor>(ctx->bsd);
+		delete ctxo;
+		*context = nullptr;
+		return ASTCENC_ERR_DLOPEN_FAILED;
+	}
+#else
 	init_block_size_descriptor(ctx->config.privateProfile, config.block_x, config.block_y, config.block_z,
 	                           can_omit_modes,
 	                           config.tune_partition_count_limit,
 	                           static_cast<float>(config.tune_block_mode_limit) / 100.0f,
 	                           *ctx->bsd);
+#endif
 
 #if !defined(ASTCENC_DECOMPRESS_ONLY)
 	// Do setup only needed by compression
diff --git a/Source/astcenc_internal.h b/Source/astcenc_internal.h
index 4d31a5f111df6b24d41ca44122dc79d26f7ee97a..03a0b72d1e9491c34e9f70c6eda3a8686ada9ff3 100644
--- a/Source/astcenc_internal.h
+++ b/Source/astcenc_internal.h
@@ -1262,7 +1262,11 @@ struct astcenc_contexti
  * @param      mode_cutoff              The block mode percentile cutoff [0-1].
  * @param[out] bsd                      The descriptor to initialize.
  */
+#ifdef ASTC_CUSTOMIZED_ENABLE
+bool init_block_size_descriptor(
+#else
 void init_block_size_descriptor(
+#endif
 	QualityProfile privateProfile,
 	unsigned int x_texels,
 	unsigned int y_texels,