diff --git a/src/gprs_coding_scheme.cpp b/src/gprs_coding_scheme.cpp
index 4f1db1df..8601d4f5 100644
--- a/src/gprs_coding_scheme.cpp
+++ b/src/gprs_coding_scheme.cpp
@@ -28,39 +28,40 @@ static struct {
 		unsigned int data_header_bits;
 	} uplink, downlink;
 	unsigned int data_bytes;
+	unsigned int optional_padding_bits;
 	const char *name;
 	GprsCodingScheme::HeaderType data_hdr;
 	GprsCodingScheme::Family family;
 } mcs_info[GprsCodingScheme::NUM_SCHEMES] = {
-	{{0, 0},   {0, 0},    0, "UNKNOWN",
+	{{0, 0},   {0, 0},    0,  0, "UNKNOWN",
 		GprsCodingScheme::HEADER_INVALID, GprsCodingScheme::FAMILY_INVALID},
-	{{23, 0},  {23, 0},  20, "CS-1",
+	{{23, 0},  {23, 0},  20,  0, "CS-1",
 		GprsCodingScheme::HEADER_GPRS_DATA, GprsCodingScheme::FAMILY_INVALID},
-	{{33, 7},  {33, 7},  30, "CS-2",
+	{{33, 7},  {33, 7},  30,  0, "CS-2",
 		GprsCodingScheme::HEADER_GPRS_DATA, GprsCodingScheme::FAMILY_INVALID},
-	{{39, 3},  {39, 3},  36, "CS-3",
+	{{39, 3},  {39, 3},  36,  0, "CS-3",
 		GprsCodingScheme::HEADER_GPRS_DATA, GprsCodingScheme::FAMILY_INVALID},
-	{{53, 7},  {53, 7},  50, "CS-4",
+	{{53, 7},  {53, 7},  50,  0, "CS-4",
 		GprsCodingScheme::HEADER_GPRS_DATA, GprsCodingScheme::FAMILY_INVALID},
 
-	{{26, 1},  {26, 1},  22, "MCS-1",
+	{{26, 1},  {26, 1},  22,  0, "MCS-1",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3, GprsCodingScheme::FAMILY_C},
-	{{32, 1},  {32, 1},  28, "MCS-2",
+	{{32, 1},  {32, 1},  28,  0, "MCS-2",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3, GprsCodingScheme::FAMILY_B},
-	{{41, 1},  {41, 1},  37, "MCS-3",
+	{{41, 1},  {41, 1},  37, 48, "MCS-3",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3, GprsCodingScheme::FAMILY_A},
-	{{48, 1},  {48, 1},  44, "MCS-4",
+	{{48, 1},  {48, 1},  44,  0, "MCS-4",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3, GprsCodingScheme::FAMILY_C},
 
-	{{60, 7},  {59, 6},  56, "MCS-5",
+	{{60, 7},  {59, 6},  56,  0, "MCS-5",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_2, GprsCodingScheme::FAMILY_B},
-	{{78, 7},  {77, 6},  74, "MCS-6",
+	{{78, 7},  {77, 6},  74, 48, "MCS-6",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_2, GprsCodingScheme::FAMILY_A},
-	{{118, 2}, {117, 4}, 56, "MCS-7",
+	{{118, 2}, {117, 4}, 56,  0, "MCS-7",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1, GprsCodingScheme::FAMILY_B},
-	{{142, 2}, {141, 4}, 68, "MCS-8",
+	{{142, 2}, {141, 4}, 68,  0, "MCS-8",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1, GprsCodingScheme::FAMILY_A},
-	{{154, 2}, {153, 4}, 74, "MCS-9",
+	{{154, 2}, {153, 4}, 74,  0, "MCS-9",
 		GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1, GprsCodingScheme::FAMILY_A},
 };
 
@@ -152,6 +153,11 @@ unsigned int GprsCodingScheme::maxDataBlockBytes() const
 	return mcs_info[m_scheme].data_bytes;
 }
 
+unsigned int GprsCodingScheme::optionalPaddingBits() const
+{
+	return mcs_info[m_scheme].optional_padding_bits;
+}
+
 unsigned int GprsCodingScheme::numDataBlocks() const
 {
 	return hdr_type_info[headerTypeData()].num_blocks;
diff --git a/src/gprs_coding_scheme.h b/src/gprs_coding_scheme.h
index e9a06a53..aec37623 100644
--- a/src/gprs_coding_scheme.h
+++ b/src/gprs_coding_scheme.h
@@ -94,6 +94,7 @@ public:
 	unsigned int numDataHeaderBitsUL() const;
 	unsigned int numDataHeaderBitsDL() const;
 	unsigned int numDataBlockHeaderBits() const;
+	unsigned int optionalPaddingBits() const;
 	const char *name() const;
 	HeaderType headerTypeData() const;
 	HeaderType headerTypeControl() const;
diff --git a/tests/edge/EdgeTest.cpp b/tests/edge/EdgeTest.cpp
index 02e9bc20..80997a4b 100644
--- a/tests/edge/EdgeTest.cpp
+++ b/tests/edge/EdgeTest.cpp
@@ -92,7 +92,8 @@ static void check_coding_scheme(GprsCodingScheme& cs, GprsCodingScheme::Mode mod
 	OSMO_ASSERT(cs.isFamilyCompatible(new_cs));
 	OSMO_ASSERT(cs.isCompatible(new_cs));
 	if (need_padding) {
-		OSMO_ASSERT(new_cs.maxDataBlockBytes() > cs.maxDataBlockBytes());
+		OSMO_ASSERT(new_cs.maxDataBlockBytes() ==
+			new_cs.optionalPaddingBits()/8 + cs.maxDataBlockBytes());
 	} else {
 		OSMO_ASSERT(new_cs.maxDataBlockBytes() == cs.maxDataBlockBytes());
 	}