diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b0eebd1..211fe7a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -61,16 +61,11 @@ jobs:
           - macos-latest
           - windows-latest
         go_version:
-          - "1.15"
-          - "1.16"
-          - "1.17"
-          - "1.18"
-          - "1.19"
-          - "1.20"
-          - "1.21"
-          - "1.22"
-          - "1.23"
-          - "1.24"
+          # Only test versions where testing.T interface changed:
+          - "1.15"  # Base version
+          - "1.16"  # Added Setenv()
+          - "1.17"  # Representative of 1.17-1.23 (no changes)
+          - "1.24"  # Added Context() and Chdir()
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0382b5e..3acafd4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,7 +7,7 @@ All notable changes to this project will be documented in this file. See [standa
 ### Features
 
 * **testing:** Add support for Go 1.24 Context() and Chdir() methods
-* **ci:** Test against Go 1.18-1.24 in addition to existing versions
+* **ci:** Optimize test matrix - only test Go versions with testing.T changes (1.15, 1.16, 1.17, 1.24)
 * **ci:** Upgrade all GitHub Actions to latest versions (v4-v6)
 
 ## 0.1.0 (2021-11-22)