diff --git a/speck-simd.cpp b/speck-simd.cpp
index 49863673..dd6e1cfb 100644
--- a/speck-simd.cpp
+++ b/speck-simd.cpp
@@ -896,8 +896,8 @@ void SPECK64_Enc_Block(uint32x4_p &block0, uint32x4_p &block1,
     }
 
 #if defined(CRYPTOPP_BIG_ENDIAN)
-    const uint8x16_p m3 = {11,10,9,8, 27,26,25,24, 15,14,13,12, 31,30,29,28};
-    const uint8x16_p m4 = {3,2,1,0, 19,18,17,16, 7,6,5,4, 23,22,21,20};
+    const uint8x16_p m3 = {19,18,17,16, 3,2,1,0, 23,22,21,20, 7,6,5,4};
+    const uint8x16_p m4 = {27,26,25,24, 11,10,9,8, 31,30,29,28, 15,14,13,12};
 #else
     const uint8x16_p m3 = {3,2,1,0, 19,18,17,16, 7,6,5,4, 23,22,21,20};
     const uint8x16_p m4 = {11,10,9,8, 27,26,25,24, 15,14,13,12, 31,30,29,28};
@@ -936,8 +936,8 @@ void SPECK64_Dec_Block(uint32x4_p &block0, uint32x4_p &block1,
     }
 
 #if defined(CRYPTOPP_BIG_ENDIAN)
-    const uint8x16_p m3 = {11,10,9,8, 27,26,25,24, 15,14,13,12, 31,30,29,28};
-    const uint8x16_p m4 = {3,2,1,0, 19,18,17,16, 7,6,5,4, 23,22,21,20};
+    const uint8x16_p m3 = {19,18,17,16, 3,2,1,0, 23,22,21,20, 7,6,5,4};
+    const uint8x16_p m4 = {27,26,25,24, 11,10,9,8, 31,30,29,28, 15,14,13,12};
 #else
     const uint8x16_p m3 = {3,2,1,0, 19,18,17,16, 7,6,5,4, 23,22,21,20};
     const uint8x16_p m4 = {11,10,9,8, 27,26,25,24, 15,14,13,12, 31,30,29,28};
@@ -994,8 +994,8 @@ void SPECK64_Enc_6_Blocks(uint32x4_p &block0, uint32x4_p &block1,
     }
 
 #if defined(CRYPTOPP_BIG_ENDIAN)
-    const uint8x16_p m3 = {11,10,9,8, 27,26,25,24, 15,14,13,12, 31,30,29,28};
-    const uint8x16_p m4 = {3,2,1,0, 19,18,17,16, 7,6,5,4, 23,22,21,20};
+    const uint8x16_p m3 = {19,18,17,16, 3,2,1,0, 23,22,21,20, 7,6,5,4};
+    const uint8x16_p m4 = {27,26,25,24, 11,10,9,8, 31,30,29,28, 15,14,13,12};
 #else
     const uint8x16_p m3 = {3,2,1,0, 19,18,17,16, 7,6,5,4, 23,22,21,20};
     const uint8x16_p m4 = {11,10,9,8, 27,26,25,24, 15,14,13,12, 31,30,29,28};
@@ -1056,8 +1056,8 @@ void SPECK64_Dec_6_Blocks(uint32x4_p &block0, uint32x4_p &block1,
     }
 
 #if defined(CRYPTOPP_BIG_ENDIAN)
-    const uint8x16_p m3 = {11,10,9,8, 27,26,25,24, 15,14,13,12, 31,30,29,28};
-    const uint8x16_p m4 = {3,2,1,0, 19,18,17,16, 7,6,5,4, 23,22,21,20};
+    const uint8x16_p m3 = {19,18,17,16, 3,2,1,0, 23,22,21,20, 7,6,5,4};
+    const uint8x16_p m4 = {27,26,25,24, 11,10,9,8, 31,30,29,28, 15,14,13,12};
 #else
     const uint8x16_p m3 = {3,2,1,0, 19,18,17,16, 7,6,5,4, 23,22,21,20};
     const uint8x16_p m4 = {11,10,9,8, 27,26,25,24, 15,14,13,12, 31,30,29,28};