diff --git a/.github/workflows.src/build.inc.yml b/.github/workflows.src/build.inc.yml
index b24dc532790..b2ee72888a5 100644
--- a/.github/workflows.src/build.inc.yml
+++ b/.github/workflows.src/build.inc.yml
@@ -236,7 +236,16 @@
         <%- endif %>
         PKG_PLATFORM: "<< tgt.platform >>"
         PKG_PLATFORM_VERSION: "<< tgt.platform_version >>"
+        <%- if tgt.platform_version == "x86_64" %>
+        # Run fewer tests on x86_64, since the test runner is very slow.
+        PKG_TEST_FILES: "test_dump*.py test_backend_*.py test_database.py test_server_*.py test_edgeql_ddl.py test_session.py"
+        <%- endif %>
       run: |
+        <%- if tgt.platform_version == "x86_64" %>
+        # Bump shmmax and shmall to avoid test failures.
+        sudo sysctl -w kern.sysv.shmmax=12582912
+        sudo sysctl -w kern.sysv.shmall=12582912
+        <%- endif %>
         edgedb-pkg/integration/macos/test.sh
 <%- endfor %>
 
diff --git a/.github/workflows/dryrun.yml b/.github/workflows/dryrun.yml
index 272cb0f0dd7..da6d3096b99 100644
--- a/.github/workflows/dryrun.yml
+++ b/.github/workflows/dryrun.yml
@@ -1404,7 +1404,12 @@ jobs:
         PKG_SUBDIST: "nightly"
         PKG_PLATFORM: "macos"
         PKG_PLATFORM_VERSION: "x86_64"
+        # Run fewer tests on x86_64, since the test runner is very slow.
+        PKG_TEST_FILES: "test_dump*.py test_backend_*.py test_database.py test_server_*.py test_edgeql_ddl.py test_session.py"
       run: |
+        # Bump shmmax and shmall to avoid test failures.
+        sudo sysctl -w kern.sysv.shmmax=12582912
+        sudo sysctl -w kern.sysv.shmall=12582912
         edgedb-pkg/integration/macos/test.sh
 
   test-macos-aarch64:
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 463abe52a15..cc3ecbe17fe 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -1409,7 +1409,12 @@ jobs:
         PKG_SUBDIST: "nightly"
         PKG_PLATFORM: "macos"
         PKG_PLATFORM_VERSION: "x86_64"
+        # Run fewer tests on x86_64, since the test runner is very slow.
+        PKG_TEST_FILES: "test_dump*.py test_backend_*.py test_database.py test_server_*.py test_edgeql_ddl.py test_session.py"
       run: |
+        # Bump shmmax and shmall to avoid test failures.
+        sudo sysctl -w kern.sysv.shmmax=12582912
+        sudo sysctl -w kern.sysv.shmall=12582912
         edgedb-pkg/integration/macos/test.sh
 
   test-macos-aarch64:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 02f0d26f91e..4fd287bbd70 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -1000,7 +1000,12 @@ jobs:
       env:
         PKG_PLATFORM: "macos"
         PKG_PLATFORM_VERSION: "x86_64"
+        # Run fewer tests on x86_64, since the test runner is very slow.
+        PKG_TEST_FILES: "test_dump*.py test_backend_*.py test_database.py test_server_*.py test_edgeql_ddl.py test_session.py"
       run: |
+        # Bump shmmax and shmall to avoid test failures.
+        sudo sysctl -w kern.sysv.shmmax=12582912
+        sudo sysctl -w kern.sysv.shmall=12582912
         edgedb-pkg/integration/macos/test.sh
 
   test-macos-aarch64:
diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 3731edc94d3..c6721e0c95e 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -1043,7 +1043,12 @@ jobs:
         PKG_SUBDIST: "testing"
         PKG_PLATFORM: "macos"
         PKG_PLATFORM_VERSION: "x86_64"
+        # Run fewer tests on x86_64, since the test runner is very slow.
+        PKG_TEST_FILES: "test_dump*.py test_backend_*.py test_database.py test_server_*.py test_edgeql_ddl.py test_session.py"
       run: |
+        # Bump shmmax and shmall to avoid test failures.
+        sudo sysctl -w kern.sysv.shmmax=12582912
+        sudo sysctl -w kern.sysv.shmall=12582912
         edgedb-pkg/integration/macos/test.sh
 
   test-macos-aarch64: