diff --git a/.github/workflows/fw-test-emu.yml b/.github/workflows/fw-test-emu.yml
index 130e6745a2..ca1cab8f5c 100644
--- a/.github/workflows/fw-test-emu.yml
+++ b/.github/workflows/fw-test-emu.yml
@@ -13,6 +13,9 @@ on:
       rom-logging:
         default: true
         type: boolean
+      slow-tests
+        default: false
+        type: boolean
 
 jobs:
   build_and_test:
@@ -58,17 +61,27 @@ jobs:
         run: |
           export CALIPTRA_PREBUILT_FW_DIR=/tmp/caliptra-test-firmware
 
-          FEATURE_FLAG=
+          FEATURE_FLAG="--features="
 
           if [ "${{ inputs.trng }}" == "external" ] || [ -z "${{ inputs.trng }}" ]; then
             echo Using external TRNG
           elif [ "${{ inputs.trng }}" == "internal" ]; then
             echo Using internal TRNG
-            FEATURE_FLAG="--features=itrng"
+            FEATURE_FLAG+=",itrng"
           else
             echo "Unexpected inputs.trng: ${{ inputs.rom-logging }}"
           fi
 
+          if [ "${{ inputs.slow-tests }}" == "false" ] || [ -z "${{ inputs.slow-tests }}" ]; then
+            echo Ignoring slow tests
+          elif [ "${{ inputs.slow_tests }}" == "true" ]; then
+            echo Including slow tests
+            FEATURE_FLAG+=",slow_tests"
+          else
+            echo "Unexpected inputs.slow-tests: ${{ slow-tests }}"
+            exit 1
+          fi
+
           if [ "${{ inputs.rom-logging }}" == "true" ] || [ -z "${{ inputs.rom-logging }}" ]; then
             export CPTRA_ROM_TYPE=ROM_WITH_UART
           elif [ "${{ inputs.rom-logging }}" == false ]; then
@@ -78,6 +91,8 @@ jobs:
             exit 1
           fi
 
+          echo Using feature flags "${FEATURE_FLAG}"
+
           # Workaround https://github.com/nextest-rs/nextest/issues/267
           export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib
 
diff --git a/.github/workflows/nightly-release.yml b/.github/workflows/nightly-release.yml
index 2ca9f2e748..c96f619c3d 100644
--- a/.github/workflows/nightly-release.yml
+++ b/.github/workflows/nightly-release.yml
@@ -90,6 +90,7 @@ jobs:
       artifact-suffix: -sw-emulator-realtime-etrng-log
       trng: external
       rom-logging: true
+      slow-tests: true
 
   sw-emulator-full-suite-etrng-nolog:
     name: sw-emulator Suite (etrng, nolog)
@@ -100,6 +101,7 @@ jobs:
       artifact-suffix: -sw-emulator-realtime-etrng-nolog
       trng: external
       rom-logging: false
+      slow-tests: true
 
   sw-emulator-full-suite-itrng-log:
     name: sw-emulator Suite (itrng, log)
@@ -110,6 +112,7 @@ jobs:
       artifact-suffix: -sw-emulator-realtime-itrng-log
       trng: internal
       rom-logging: true
+      slow-tests: false
 
   sw-emulator-full-suite-itrng-nolog:
     name: sw-emulator Suite (itrng, nolog)
@@ -120,6 +123,7 @@ jobs:
       artifact-suffix: -sw-emulator-realtime-itrng-nolog
       trng: internal
       rom-logging: false
+      slow-tests: false