diff --git a/packages/ocaml-variants/ocaml-variants.4.14.1+BER/opam b/packages/ocaml-variants/ocaml-variants.4.14.1+BER/opam
index 015a91aefc82..26582e83b0cd 100644
--- a/packages/ocaml-variants/ocaml-variants.4.14.1+BER/opam
+++ b/packages/ocaml-variants/ocaml-variants.4.14.1+BER/opam
@@ -77,4 +77,8 @@ depopts: [
   "ocaml-option-nnp"
   "ocaml-option-nnpchecker"
 ]
-available: !(os = "macos" & arch = "arm64") & os != "win32"
+conflicts: [
+  "ocaml-option-32bit"
+  "ocaml-option-bytecode-only"
+]
+available: os != "win32"
diff --git a/packages/ocaml-variants/ocaml-variants.5.3.0+BER/opam b/packages/ocaml-variants/ocaml-variants.5.3.0+BER/opam
index abcb3838658e..0f763f0c34ce 100644
--- a/packages/ocaml-variants/ocaml-variants.5.3.0+BER/opam
+++ b/packages/ocaml-variants/ocaml-variants.5.3.0+BER/opam
@@ -13,7 +13,13 @@ depends: [
   "base-unix" {post}
   "base-bigarray" {post}
   "base-threads" {post}
+  "base-domains" {post}
+  "base-nnp" {post}
+  "base-effects" {post}
   "base-metaocaml-ocamlfind" {post}
+
+  # All the 32-bit architectures are bytecode-only
+  "ocaml-option-bytecode-only" {arch != "arm64" & arch != "x86_64" & arch != "s390x" & arch != "riscv64" & arch != "ppc64"}
 ]
 conflict-class: "ocaml-core-compiler"
 flags: compiler
@@ -26,27 +32,25 @@ build: [
     "-C"
     "--with-afl" {ocaml-option-afl:installed}
     "--disable-native-compiler" {ocaml-option-bytecode-only:installed}
-    "--disable-force-safe-string" {ocaml-option-default-unsafe-string:installed}
-    "DEFAULT_STRING=unsafe" {ocaml-option-default-unsafe-string:installed}
     "--disable-flat-float-array" {ocaml-option-no-flat-float-array:installed}
     "--enable-flambda" {ocaml-option-flambda:installed}
     "--enable-frame-pointers" {ocaml-option-fp:installed}
-    "--disable-naked-pointers" {ocaml-option-nnp:installed}
-    "--enable-naked-pointers-checker" {ocaml-option-nnpchecker:installed}
-    "CC=cc" {!ocaml-option-32bit:installed & !ocaml-option-musl:installed & (os="openbsd"|os="macos")}
+    "--without-zstd" {ocaml-option-no-compression:installed}
+    "--enable-tsan" {ocaml-option-tsan:installed}
+    "CC=cc" {!ocaml-option-32bit:installed & !ocaml-option-musl:installed & (os = "openbsd" | os = "macos")}
+    "CC=clang" {ocaml-option-tsan:installed & (os="macos")}
     "CC=musl-gcc" {ocaml-option-musl:installed & os-distribution!="alpine"}
-    "CFLAGS=-Os" {ocaml-option-musl:installed}
+    "CFLAGS=-Os" {ocaml-option-musl:installed & arch != "arm64"}
+    "CFLAGS=-Os -mno-outline-atomics" {ocaml-option-musl:installed & arch = "arm64"}
+    "LDFLAGS=-Wl,--no-as-needed,-ldl" {ocaml-option-leak-sanitizer:installed | (ocaml-option-address-sanitizer:installed & os!="macos")}
+    "CC=gcc -ldl -fsanitize=leak -fno-omit-frame-pointer -O1 -g" {ocaml-option-leak-sanitizer:installed}
+    "CC=gcc -ldl -fsanitize=address -fno-omit-frame-pointer -O1 -g" {ocaml-option-address-sanitizer:installed & os!="macos"}
+    "CC=clang -fsanitize=address -fno-omit-frame-pointer -O1 -g" {ocaml-option-address-sanitizer:installed & os="macos"}
     "CC=gcc -m32" {ocaml-option-32bit:installed & os="linux"}
     "CC=gcc -Wl,-read_only_relocs,suppress -arch i386 -m32" {ocaml-option-32bit:installed & os="macos"}
-    "ASPP=cc -c" {!ocaml-option-32bit:installed & !ocaml-option-musl:installed & (os="openbsd"|os="macos")}
     "ASPP=musl-gcc -c" {ocaml-option-musl:installed & os-distribution!="alpine"}
-    "ASPP=gcc -m32 -c" {ocaml-option-32bit:installed & os="linux"}
-    "ASPP=gcc -arch i386 -m32 -c" {ocaml-option-32bit:installed & os="macos"}
-    "AS=as --32" {ocaml-option-32bit:installed & os="linux"}
-    "AS=as -arch i386" {ocaml-option-32bit:installed & os="macos"}
     "--host=i386-linux" {ocaml-option-32bit:installed & os="linux"}
     "--host=i386-apple-darwin13.2.0" {ocaml-option-32bit:installed & os="macos"}
-    "PARTIALLD=ld -r -melf_i386" {ocaml-option-32bit:installed & os="linux"}
     "LIBS=-static" {ocaml-option-static:installed}
     "--disable-warn-error"
   ]
@@ -67,13 +71,18 @@ depopts: [
   "ocaml-option-32bit"
   "ocaml-option-afl"
   "ocaml-option-bytecode-only"
-  "ocaml-option-default-unsafe-string"
   "ocaml-option-no-flat-float-array"
   "ocaml-option-flambda"
   "ocaml-option-fp"
+  "ocaml-option-no-compression"
   "ocaml-option-musl"
+  "ocaml-option-leak-sanitizer"
+  "ocaml-option-address-sanitizer"
   "ocaml-option-static"
-  "ocaml-option-nnp"
-  "ocaml-option-nnpchecker"
+  "ocaml-option-tsan"
 ]
-available: !(os = "macos" & arch = "arm64") & os != "win32" & arch != "arm32" & arch != "x86_32"
+conflicts: [
+  "ocaml-option-32bit"
+  "ocaml-option-bytecode-only"
+]
+available: os != "win32"