diff --git a/cardano-crypto-class/cardano-crypto-class.cabal b/cardano-crypto-class/cardano-crypto-class.cabal
index 20ba0362c..bd3e5c576 100644
--- a/cardano-crypto-class/cardano-crypto-class.cabal
+++ b/cardano-crypto-class/cardano-crypto-class.cabal
@@ -39,6 +39,15 @@ flag secp256k1-support
   default: True
   manual: True
 
+flag use-haskell-clibs
+  description:
+    Use Haskell *-clib packages (blst-clib, sodium-clib, secp256k1-clib) instead
+    of system-provided C libraries via pkg-config. Don't enable this flag when
+    building cardano-node! It is there for less sensitive clients, such as
+    Plinth.
+  default: False
+  manual: True
+
 common base
   build-depends: base >=4.18 && <5
 
@@ -143,13 +152,19 @@ library
     th-compat,
     transformers,
     vector,
+  if flag(use-haskell-clibs)
+    build-depends:
+      blst-clib >=0.3.14,
+      sodium-clib
+    ghc-options: -Wno-unused-packages
+  else
+    pkgconfig-depends:
+      libblst,
+      libsodium
 
   if impl(ghc <9.0.0)
     build-depends:
       integer-gmp
-  pkgconfig-depends:
-    libblst >=0.3.14,
-    libsodium,
 
   c-sources: cbits/blst_util.c
   include-dirs: cbits
@@ -161,7 +176,10 @@ library
       Cardano.Crypto.SECP256K1.C
       Cardano.Crypto.SECP256K1.Constants
 
-    pkgconfig-depends: libsecp256k1
+    if flag(use-haskell-clibs)
+      build-depends: secp256k1-clib
+    else
+      pkgconfig-depends: libsecp256k1
     cpp-options: -DSECP256K1_ENABLED
 
 library testlib
diff --git a/cardano-crypto-praos/cardano-crypto-praos.cabal b/cardano-crypto-praos/cardano-crypto-praos.cabal
index b413ad184..19f7d99c1 100644
--- a/cardano-crypto-praos/cardano-crypto-praos.cabal
+++ b/cardano-crypto-praos/cardano-crypto-praos.cabal
@@ -60,6 +60,14 @@ flag external-libsodium-vrf
   default: True
   manual: True
 
+flag use-haskell-clibs
+  description:
+    Use Haskell *-clib packages (sodium-clib) instead of system-provided C
+    libraries via pkg-config. Don't enable this flag when building cardano-node!
+    It is there for less sensitive clients, such as Plinth.
+  default: False
+  manual: True
+
 common base
   build-depends: base >=4.18 && <5
 
@@ -91,7 +99,11 @@ library
     nothunks,
     primitive,
 
-  pkgconfig-depends: libsodium
+  if flag(use-haskell-clibs)
+    build-depends: sodium-clib
+    ghc-options: -Wno-unused-packages
+  else
+    pkgconfig-depends: libsodium
 
   if !flag(external-libsodium-vrf)
     c-sources: