diff --git a/nix/cbmc/default.nix b/nix/cbmc/default.nix
index bc649c793..946e2d1e1 100644
--- a/nix/cbmc/default.nix
+++ b/nix/cbmc/default.nix
@@ -15,12 +15,12 @@ buildEnv {
   paths =
     builtins.attrValues {
       cbmc = cbmc.overrideAttrs (_: {
-        version = "6.9.0";
+        version = "6.10.0";
         src = fetchFromGitHub {
           owner = "diffblue";
           repo = "cbmc";
-          hash = "sha256-SMJBnzoyTwcwJa9L2X1iX2W4Z/Mwoirf8EXfoyG0dRI=";
-          tag = "cbmc-6.9.0";
+          hash = "sha256-GCagpb2TFhOEH+lzMth+PWiJxlEw0L+H1DYUEQoMF3g=";
+          tag = "cbmc-6.10.0";
         };
       });
       litani = callPackage ./litani.nix { }; # 1.29.0
diff --git a/proofs/cbmc/sign_verify_internal/Makefile b/proofs/cbmc/sign_verify_internal/Makefile
index 6311f1585..c01c71fbc 100644
--- a/proofs/cbmc/sign_verify_internal/Makefile
+++ b/proofs/cbmc/sign_verify_internal/Makefile
@@ -46,7 +46,7 @@ USE_DYNAMIC_FRAMES=1
 
 # Disable any setting of EXTERNAL_SAT_SOLVER, and choose SMT backend instead
 EXTERNAL_SAT_SOLVER=
-CBMCFLAGS=--external-smt2-solver $(PROOF_ROOT)/lib/z3_no_bv_extract --z3
+CBMCFLAGS=--smt2
 
 FUNCTION_NAME = sign_verify_internal