diff --git a/tvix/boot/tests/default.nix b/tvix/boot/tests/default.nix
index 31f69d11c..26640d6e9 100644
--- a/tvix/boot/tests/default.nix
+++ b/tvix/boot/tests/default.nix
@@ -53,7 +53,7 @@ let
         buildCommand = ''
           touch $out
           # Ensure we can construct http clients.
-          export SSL_CERT_FILE="${pkgs.cacert.out}/etc/ssl/certs/ca-bundle.crt"
+          export SSL_CERT_FILE=/dev/null
 
           ${preStart}
 
diff --git a/tvix/castore/default.nix b/tvix/castore/default.nix
index 03a12b6c2..9c210884f 100644
--- a/tvix/castore/default.nix
+++ b/tvix/castore/default.nix
@@ -3,7 +3,7 @@
 (depot.tvix.crates.workspaceMembers.tvix-castore.build.override {
   runTests = true;
   testPreRun = ''
-    export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt;
+    export SSL_CERT_FILE=/dev/null
   '';
 }).overrideAttrs (old: rec {
   meta.ci.targets = [ "integration-tests" ] ++ lib.filter (x: lib.hasPrefix "with-features" x || x == "no-features") (lib.attrNames passthru);
@@ -13,13 +13,13 @@
       # virtiofs feature currently fails to build on Darwin
       ++ lib.optional pkgs.stdenv.isLinux "virtiofs");
     override.testPreRun = ''
-      export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt
+      export SSL_CERT_FILE=/dev/null
     '';
   }) // {
     integration-tests = depot.tvix.crates.workspaceMembers.${old.crateName}.build.override (old: {
       runTests = true;
       testPreRun = ''
-        export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt;
+        export SSL_CERT_FILE=/dev/null
         export PATH="$PATH:${pkgs.lib.makeBinPath [ pkgs.cbtemulator pkgs.google-cloud-bigtable-tool ]}"
       '';
       features = old.features ++ [ "integration" ];
diff --git a/tvix/cli/default.nix b/tvix/cli/default.nix
index 3ed7a7ccf..90394f6d2 100644
--- a/tvix/cli/default.nix
+++ b/tvix/cli/default.nix
@@ -3,7 +3,7 @@
 (depot.tvix.crates.workspaceMembers.tvix-cli.build.override {
   runTests = true;
   testPreRun = ''
-    export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt;
+    export SSL_CERT_FILE=/dev/null
   '';
 }).overrideAttrs (finalAttrs: previousAttrs:
 
@@ -30,7 +30,7 @@ let
   mkExprBenchmark = { expr, description }:
     let name = "tvix-cli-benchmark-${description}"; in
     (pkgs.runCommand name { } ''
-      export SSL_CERT_FILE=${pkgs.cacert.out}/etc/ssl/certs/ca-bundle.crt
+      export SSL_CERT_FILE=/dev/null
       ${lib.escapeShellArgs [
         "${pkgs.time}/bin/time"
         "--format" "${benchmark-gnutime-format-string description}"
@@ -54,7 +54,7 @@ let
       name = "tvix-eval-test-${builtins.replaceStrings [".drv"] ["-drv"] attrpath}";
     in
     (pkgs.runCommand name { } ''
-      export SSL_CERT_FILE=${pkgs.cacert.out}/etc/ssl/certs/ca-bundle.crt
+      export SSL_CERT_FILE=/dev/null
       TVIX_OUTPUT=$(${tvix-cli}/bin/tvix -E '(import ${pkgs.path} {}).${attrpath}')
       EXPECTED='${/* the verbatim expected Tvix output: */ "=> \"${builtins.unsafeDiscardStringContext expectedPath}\" :: string"}'
 
diff --git a/tvix/glue/default.nix b/tvix/glue/default.nix
index 14c7e214f..e2b36e94b 100644
--- a/tvix/glue/default.nix
+++ b/tvix/glue/default.nix
@@ -3,7 +3,7 @@
 (depot.tvix.crates.workspaceMembers.tvix-glue.build.override {
   runTests = true;
   testPreRun = ''
-    export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt;
+    export SSL_CERT_FILE=/dev/null
   '';
 }).overrideAttrs (old: rec {
   meta.ci.targets = lib.filter (x: lib.hasPrefix "with-features" x || x == "no-features") (lib.attrNames passthru);
@@ -11,7 +11,7 @@
     inherit (old) crateName;
     features = [ "nix_tests" ];
     override.testPreRun = ''
-      export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt;
+      export SSL_CERT_FILE=/dev/null
     '';
   };
 })
diff --git a/tvix/store/default.nix b/tvix/store/default.nix
index 3fe47fe60..d5d4609be 100644
--- a/tvix/store/default.nix
+++ b/tvix/store/default.nix
@@ -25,7 +25,7 @@ in
 (depot.tvix.crates.workspaceMembers.tvix-store.build.override (old: {
   runTests = true;
   testPreRun = ''
-    export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt
+    export SSL_CERT_FILE=/dev/null
   '';
   features = old.features
     # virtiofs feature currently fails to build on Darwin
@@ -41,13 +41,13 @@ in
       # virtiofs feature currently fails to build on Darwin
       ++ lib.optional pkgs.stdenv.isLinux "virtiofs");
     override.testPreRun = ''
-      export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt
+      export SSL_CERT_FILE=/dev/null
     '';
   }) // {
     integration-tests = depot.tvix.crates.workspaceMembers.${old.crateName}.build.override (old: {
       runTests = true;
       testPreRun = ''
-        export SSL_CERT_FILE=${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt;
+        export SSL_CERT_FILE=/dev/null
         export PATH="$PATH:${pkgs.lib.makeBinPath [ pkgs.cbtemulator pkgs.google-cloud-bigtable-tool ]}"
       '';
       features = old.features ++ [ "integration" ];