diff --git a/include/seqan3/alphabet/alphabet_base.hpp b/include/seqan3/alphabet/alphabet_base.hpp
index d3d7043c088..5f1aa12de28 100644
--- a/include/seqan3/alphabet/alphabet_base.hpp
+++ b/include/seqan3/alphabet/alphabet_base.hpp
@@ -217,8 +217,17 @@ class alphabet_base
      */
     static constexpr rank_type char_to_rank_table(char_type const chr) noexcept
     {
+#if SEQAN3_WORKAROUND_GCC_99318
+#   pragma GCC diagnostic push
+#   pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+        using index_t = std::make_unsigned_t<char_type>;
+        index_t const id = static_cast<index_t>(chr);
+        return derived_type::char_to_rank[id];
+#   pragma GCC diagnostic pop
+#else // ^^^ workaround / no workaround vvv
         using index_t = std::make_unsigned_t<char_type>;
         return derived_type::char_to_rank[static_cast<index_t>(chr)];
+#endif // SEQAN3_WORKAROUND_GCC_99318
     }
 
 public:
diff --git a/include/seqan3/core/platform.hpp b/include/seqan3/core/platform.hpp
index fb9b0fdc35e..162e5f7571a 100644
--- a/include/seqan3/core/platform.hpp
+++ b/include/seqan3/core/platform.hpp
@@ -323,6 +323,15 @@
 #   endif
 #endif
 
+//!\brief See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99318
+#ifndef SEQAN3_WORKAROUND_GCC_99318 // not yet fixed, this is a regression since gcc-10
+#   if defined(__GNUC__) && (__GNUC__ >= 10)
+#       define SEQAN3_WORKAROUND_GCC_99318 1
+#   else
+#       define SEQAN3_WORKAROUND_GCC_99318 0
+#   endif
+#endif
+
 /*!\brief This is needed to support CentOS 7 or RHEL 7; Newer CentOS's include a more modern default-gcc version making
  *        this macro obsolete.
  *