diff --git a/hash/murmur/common.cpp b/hash/murmur/common.cpp
index e504f76e..8c62ac38 100644
--- a/hash/murmur/common.cpp
+++ b/hash/murmur/common.cpp
@@ -20,8 +20,8 @@ namespace cruft::hash::murmur {
         uint32_t h = 0;
 
         switch (len % sizeof (uint32_t)) {
-            case 3: h += bytes[2] << 16;
-            case 2: h += bytes[1] <<  8;
+            case 3: h += bytes[2] << 16; [[fallthrough]];
+            case 2: h += bytes[1] <<  8; [[fallthrough]];
             case 1: h += bytes[0];
                     break;
 
@@ -43,12 +43,12 @@ namespace cruft::hash::murmur {
         uint64_t h = 0;
 
         switch (len % sizeof (uint64_t)) {
-            case 7: h += uint64_t(bytes[6]) << 48;
-            case 6: h += uint64_t(bytes[5]) << 40;
-            case 5: h += uint64_t(bytes[4]) << 32;
-            case 4: h += uint64_t(bytes[3]) << 24;
-            case 3: h += uint64_t(bytes[2]) << 16;
-            case 2: h += uint64_t(bytes[1]) <<  8;
+            case 7: h += uint64_t(bytes[6]) << 48; [[fallthrough]];
+            case 6: h += uint64_t(bytes[5]) << 40; [[fallthrough]];
+            case 5: h += uint64_t(bytes[4]) << 32; [[fallthrough]];
+            case 4: h += uint64_t(bytes[3]) << 24; [[fallthrough]];
+            case 3: h += uint64_t(bytes[2]) << 16; [[fallthrough]];
+            case 2: h += uint64_t(bytes[1]) <<  8; [[fallthrough]];
             case 1: h += uint64_t(bytes[0]);
                     break;
 
@@ -70,20 +70,20 @@ namespace cruft::hash::murmur {
         std::array<uint32_t,4> result {0,0,0,0};
 
         switch (len % 16) {
-            case 15: result[3] |= bytes[14] << 16;
-            case 14: result[3] |= bytes[13] <<  8;
-            case 13: result[3] |= bytes[12] <<  0;
-            case 12: result[2] |= bytes[11] << 24;
-            case 11: result[2] |= bytes[10] << 16;
-            case 10: result[2] |= bytes[ 9] <<  8;
-            case  9: result[2] |= bytes[ 8] <<  0;
-            case  8: result[1] |= bytes[ 7] << 24;
-            case  7: result[1] |= bytes[ 6] << 16;
-            case  6: result[1] |= bytes[ 5] <<  8;
-            case  5: result[1] |= bytes[ 4] <<  0;
-            case  4: result[0] |= bytes[ 3] << 24;
-            case  3: result[0] |= bytes[ 2] << 16;
-            case  2: result[0] |= bytes[ 1] <<  8;
+            case 15: result[3] |= bytes[14] << 16; [[fallthrough]];
+            case 14: result[3] |= bytes[13] <<  8; [[fallthrough]];
+            case 13: result[3] |= bytes[12] <<  0; [[fallthrough]];
+            case 12: result[2] |= bytes[11] << 24; [[fallthrough]];
+            case 11: result[2] |= bytes[10] << 16; [[fallthrough]];
+            case 10: result[2] |= bytes[ 9] <<  8; [[fallthrough]];
+            case  9: result[2] |= bytes[ 8] <<  0; [[fallthrough]];
+            case  8: result[1] |= bytes[ 7] << 24; [[fallthrough]];
+            case  7: result[1] |= bytes[ 6] << 16; [[fallthrough]];
+            case  6: result[1] |= bytes[ 5] <<  8; [[fallthrough]];
+            case  5: result[1] |= bytes[ 4] <<  0; [[fallthrough]];
+            case  4: result[0] |= bytes[ 3] << 24; [[fallthrough]];
+            case  3: result[0] |= bytes[ 2] << 16; [[fallthrough]];
+            case  2: result[0] |= bytes[ 1] <<  8; [[fallthrough]];
             case  1: result[0] |= bytes[ 0] <<  0;
                      break;
 
@@ -106,21 +106,21 @@ namespace cruft::hash::murmur {
 
         switch(len & 15)
         {
-            case 15: result[1] |= uint64_t{bytes[14]} << 48;
-            case 14: result[1] |= uint64_t{bytes[13]} << 40;
-            case 13: result[1] |= uint64_t{bytes[12]} << 32;
-            case 12: result[1] |= uint64_t{bytes[11]} << 24;
-            case 11: result[1] |= uint64_t{bytes[10]} << 16;
-            case 10: result[1] |= uint64_t{bytes[ 9]} <<  8;
-            case  9: result[1] |= uint64_t{bytes[ 8]} <<  0;
+            case 15: result[1] |= uint64_t{bytes[14]} << 48; [[fallthrough]];
+            case 14: result[1] |= uint64_t{bytes[13]} << 40; [[fallthrough]];
+            case 13: result[1] |= uint64_t{bytes[12]} << 32; [[fallthrough]];
+            case 12: result[1] |= uint64_t{bytes[11]} << 24; [[fallthrough]];
+            case 11: result[1] |= uint64_t{bytes[10]} << 16; [[fallthrough]];
+            case 10: result[1] |= uint64_t{bytes[ 9]} <<  8; [[fallthrough]];
+            case  9: result[1] |= uint64_t{bytes[ 8]} <<  0; [[fallthrough]];
 
-            case  8: result[0] |= uint64_t{bytes[ 7]} << 56;
-            case  7: result[0] |= uint64_t{bytes[ 6]} << 48;
-            case  6: result[0] |= uint64_t{bytes[ 5]} << 40;
-            case  5: result[0] |= uint64_t{bytes[ 4]} << 32;
-            case  4: result[0] |= uint64_t{bytes[ 3]} << 24;
-            case  3: result[0] |= uint64_t{bytes[ 2]} << 16;
-            case  2: result[0] |= uint64_t{bytes[ 1]} <<  8;
+            case  8: result[0] |= uint64_t{bytes[ 7]} << 56; [[fallthrough]];
+            case  7: result[0] |= uint64_t{bytes[ 6]} << 48; [[fallthrough]];
+            case  6: result[0] |= uint64_t{bytes[ 5]} << 40; [[fallthrough]];
+            case  5: result[0] |= uint64_t{bytes[ 4]} << 32; [[fallthrough]];
+            case  4: result[0] |= uint64_t{bytes[ 3]} << 24; [[fallthrough]];
+            case  3: result[0] |= uint64_t{bytes[ 2]} << 16; [[fallthrough]];
+            case  2: result[0] |= uint64_t{bytes[ 1]} <<  8; [[fallthrough]];
             case  1: result[0] |= uint64_t{bytes[ 0]} <<  0;
                      break;
 
diff --git a/parse/si.cpp b/parse/si.cpp
index e201d01c..4f477ffe 100644
--- a/parse/si.cpp
+++ b/parse/si.cpp
@@ -34,6 +34,7 @@ cruft::parse::si (cruft::view<char const*> const src)
             case 'G': case 'g': return dst * 1024 * 1024 * 1024;
             case 'T': case 't': return dst * 1024 * 1024 * 1024 * 1024;
         }
+        [[fallthrough]];
 
     default:
         return cruft::unexpected (std::errc::invalid_argument);
diff --git a/types/description.cpp b/types/description.cpp
index fe16e667..188f2960 100644
--- a/types/description.cpp
+++ b/types/description.cpp
@@ -82,6 +82,7 @@ cruft::debug::validator<cruft::types::description>::is_valid (
         WARN_RETURN (val.width == 0 || val.width > 8, false);
         WARN_RETURN (val.arity == 0 || val.arity > 16, false);
         WARN_RETURN (val.alignment == 0 || val.alignment > 64, false);
+        return true;
 
     // All bets are off. Have fun.
     case cruft::types::category::NONE: