diff --git a/.github/workflows/test-pull-request.yml b/.github/workflows/test-pull-request.yml
index 1036e83..98dd76f 100644
--- a/.github/workflows/test-pull-request.yml
+++ b/.github/workflows/test-pull-request.yml
@@ -43,6 +43,10 @@ jobs:
         uses: julia-actions/cache@v2
       - name: Build package
         uses: julia-actions/julia-buildpkg@v1
+      - name: Fix SDPA to v0.5 in Julia v1.6
+        run: |
+          julia --project=. -e 'import Pkg;
+            if VERSION < v"1.7" Pkg.add(name="SDPA", version="0.5"); Pkg.pin(name="SDPA", version="0.5") end;'
       - name: Run tests
         uses: julia-actions/julia-runtest@v1
       - name: Process coverage
diff --git a/test/Aqua.jl b/test/Aqua.jl
index 283353d..2f3e6e5 100644
--- a/test/Aqua.jl
+++ b/test/Aqua.jl
@@ -2,5 +2,10 @@ using RangeEnclosures, Test
 import Aqua
 
 @testset "Aqua tests" begin
-    Aqua.test_all(RangeEnclosures)
+    if VERSION >= v"1.7"
+        Aqua.test_all(RangeEnclosures)
+    else
+        # some tests fail in v1.6 due to problems in SDPA
+        Aqua.test_all(RangeEnclosures; stale_deps=false, deps_compat=false)
+    end
 end
diff --git a/test/Project.toml b/test/Project.toml
index e705b04..b15a09e 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -16,6 +16,6 @@ Documenter = "0.27, 1"
 # DynamicPolynomials v0.6 leads to conflict with PolyJuMP, which requires IntervalArithmetic v0.22
 DynamicPolynomials = "0.3 - 0.5, =0.5"
 IntervalOptimisation = "0.4.1"
-SDPA = "0.2 - 0.5"
+SDPA = "0.2 - 0.6"
 SumOfSquares = "0.3.6 - 0.7"
 TaylorModels = "0.3 - 0.7"